Merge remote-tracking branch 'upstream/master' into usermarksusermarks

1 files changed, 452 insertions, 372 deletions

diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index 17fbbe17b8..5518fdfa51 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -4,30 +4,44 @@
 // quickfix.c: functions for quickfix mode, using a file with error messages
 
 #include <assert.h>
+#include <errno.h>
 #include <inttypes.h>
+#include <limits.h>
 #include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
+#include <time.h>
 
-#include "nvim/api/private/helpers.h"
 #include "nvim/arglist.h"
 #include "nvim/ascii.h"
+#include "nvim/autocmd.h"
 #include "nvim/buffer.h"
 #include "nvim/charset.h"
 #include "nvim/cursor.h"
 #include "nvim/drawscreen.h"
 #include "nvim/edit.h"
 #include "nvim/eval.h"
+#include "nvim/eval/typval.h"
+#include "nvim/eval/typval_defs.h"
+#include "nvim/eval/window.h"
 #include "nvim/ex_cmds.h"
 #include "nvim/ex_cmds2.h"
+#include "nvim/ex_cmds_defs.h"
 #include "nvim/ex_docmd.h"
 #include "nvim/ex_eval.h"
 #include "nvim/ex_getln.h"
 #include "nvim/fileio.h"
 #include "nvim/fold.h"
+#include "nvim/gettext.h"
+#include "nvim/globals.h"
 #include "nvim/help.h"
+#include "nvim/highlight_defs.h"
 #include "nvim/highlight_group.h"
+#include "nvim/macros.h"
 #include "nvim/mark.h"
 #include "nvim/mbyte.h"
+#include "nvim/memfile_defs.h"
 #include "nvim/memline.h"
 #include "nvim/memory.h"
 #include "nvim/message.h"
@@ -35,14 +49,16 @@
 #include "nvim/normal.h"
 #include "nvim/option.h"
 #include "nvim/optionstr.h"
+#include "nvim/os/fs_defs.h"
 #include "nvim/os/input.h"
 #include "nvim/os/os.h"
-#include "nvim/os_unix.h"
 #include "nvim/path.h"
+#include "nvim/pos.h"
 #include "nvim/quickfix.h"
 #include "nvim/regexp.h"
 #include "nvim/search.h"
 #include "nvim/strings.h"
+#include "nvim/types.h"
 #include "nvim/ui.h"
 #include "nvim/vim.h"
 #include "nvim/window.h"
@@ -67,9 +83,9 @@ struct qfline_S {
   char *qf_module;      ///< module name for this error
   char *qf_pattern;     ///< search pattern for the error
   char *qf_text;        ///< description of the error
-  char qf_viscol;       ///< set to TRUE if qf_col and qf_end_col is
+  char qf_viscol;       ///< set to true if qf_col and qf_end_col is
   //   screen column
-  char qf_cleared;      ///< set to TRUE if line has been deleted
+  char qf_cleared;      ///< set to true if line has been deleted
   char qf_type;         ///< type of the error (mostly 'E'); 1 for :helpgrep
   char qf_valid;        ///< valid error message detected
 };
@@ -100,7 +116,7 @@ typedef struct qf_list_S {
   qfline_T *qf_ptr;          ///< pointer to the current error
   int qf_count;                 ///< number of errors (0 means empty list)
   int qf_index;                 ///< current index in the error list
-  int qf_nonevalid;             ///< TRUE if not a single valid entry found
+  int qf_nonevalid;             ///< true if not a single valid entry found
   char *qf_title;        ///< title derived from the command that created
                          ///< the error list or set by setqflist
   typval_T *qf_ctx;          ///< context set by setqflist/setloclist
@@ -176,6 +192,7 @@ enum {
   QF_NOMEM = 3,
   QF_IGNORE_LINE = 4,
   QF_MULTISCAN = 5,
+  QF_ABORT = 6,
 };
 
 /// State information used to parse lines and add entries to a quickfix/location
@@ -336,8 +353,7 @@ static const size_t LINE_MAXLEN = 4096;
 static struct fmtpattern {
   char convchar;
   char *pattern;
-} fmt_pat[FMT_PATTERNS] =
-{
+} fmt_pat[FMT_PATTERNS] = {
   { 'f', ".\\+" },      // only used when at end
   { 'n', "\\d\\+" },    // 1
   { 'l', "\\d\\+" },    // 2
@@ -368,9 +384,9 @@ static char *efmpat_to_regpat(const char *efmpat, char *regpat, efm_T *efminfo,
     return NULL;
   }
   if ((idx && idx < FMT_PATTERN_R
-       && vim_strchr("DXOPQ", efminfo->prefix) != NULL)
+       && vim_strchr("DXOPQ", (uint8_t)efminfo->prefix) != NULL)
       || (idx == FMT_PATTERN_R
-          && vim_strchr("OPQ", efminfo->prefix) == NULL)) {
+          && vim_strchr("OPQ", (uint8_t)efminfo->prefix) == NULL)) {
     semsg(_("E373: Unexpected %%%c in format string"), *efmpat);
     return NULL;
   }
@@ -452,10 +468,10 @@ static char *scanf_fmt_to_regpat(const char **pefmp, const char *efm, int len, c
 static const char *efm_analyze_prefix(const char *efmp, efm_T *efminfo)
   FUNC_ATTR_NONNULL_ALL
 {
-  if (vim_strchr("+-", *efmp) != NULL) {
+  if (vim_strchr("+-", (uint8_t)(*efmp)) != NULL) {
     efminfo->flags = *efmp++;
   }
-  if (vim_strchr("DXAEWINCZGOPQ", *efmp) != NULL) {
+  if (vim_strchr("DXAEWINCZGOPQ", (uint8_t)(*efmp)) != NULL) {
     efminfo->prefix = *efmp;
   } else {
     semsg(_("E376: Invalid %%%c in format string prefix"), *efmp);
@@ -494,7 +510,7 @@ static int efm_to_regpat(const char *efm, int len, efm_T *fmt_ptr, char *regpat)
         if (ptr == NULL) {
           return FAIL;
         }
-      } else if (vim_strchr("%\\.^$~[", *efmp) != NULL) {
+      } else if (vim_strchr("%\\.^$~[", (uint8_t)(*efmp)) != NULL) {
         *ptr++ = *efmp;  // regexp magic characters
       } else if (*efmp == '#') {
         *ptr++ = '*';
@@ -514,7 +530,7 @@ static int efm_to_regpat(const char *efm, int len, efm_T *fmt_ptr, char *regpat)
     } else {                    // copy normal character
       if (*efmp == '\\' && efmp + 1 < efm + len) {
         efmp++;
-      } else if (vim_strchr(".*^$~[", *efmp) != NULL) {
+      } else if (vim_strchr(".*^$~[", (uint8_t)(*efmp)) != NULL) {
         *ptr++ = '\\';  // escape regexp atoms
       }
       if (*efmp) {
@@ -548,9 +564,9 @@ static void free_efm_list(efm_T **efm_first)
 /// a regular expression pattern.
 static size_t efm_regpat_bufsz(char *efm)
 {
-  size_t sz = (FMT_PATTERNS * 3) + (STRLEN(efm) << 2);
+  size_t sz = (FMT_PATTERNS * 3) + (strlen(efm) << 2);
   for (int i = FMT_PATTERNS - 1; i >= 0;) {
-    sz += STRLEN(fmt_pat[i--].pattern);
+    sz += strlen(fmt_pat[i--].pattern);
   }
 #ifdef BACKSLASH_IN_FILENAME
   sz += 12;  // "%f" can become twelve chars longer (see efm_to_regpat)
@@ -562,7 +578,7 @@ static size_t efm_regpat_bufsz(char *efm)
 }
 
 /// Return the length of a 'errorformat' option part (separated by ",").
-static int efm_option_part_len(char *efm)
+static int efm_option_part_len(const char *efm)
 {
   int len;
 
@@ -607,7 +623,7 @@ static efm_T *parse_efm_option(char *efm)
       goto parse_efm_error;
     }
     // Advance to next part
-    efm = (char *)skip_to_option_part((char_u *)efm + len);       // skip comma and spaces
+    efm = skip_to_option_part(efm + len);       // skip comma and spaces
   }
 
   if (fmt_first == NULL) {      // nothing found
@@ -652,12 +668,12 @@ static int qf_get_next_str_line(qfstate_T *state)
   }
 
   char *p = vim_strchr(p_str, '\n');
-  size_t len = (p != NULL) ? (size_t)(p - p_str) + 1 : STRLEN(p_str);
+  size_t len = (p != NULL) ? (size_t)(p - p_str) + 1 : strlen(p_str);
 
   if (len > IOSIZE - 2) {
     state->linebuf = qf_grow_linebuf(state, len);
   } else {
-    state->linebuf = (char *)IObuff;
+    state->linebuf = IObuff;
     state->linelen = len;
   }
   memcpy(state->linebuf, p_str, state->linelen);
@@ -688,16 +704,16 @@ static int qf_get_next_list_line(qfstate_T *state)
     return QF_END_OF_INPUT;
   }
 
-  size_t len = STRLEN(TV_LIST_ITEM_TV(p_li)->vval.v_string);
+  size_t len = strlen(TV_LIST_ITEM_TV(p_li)->vval.v_string);
   if (len > IOSIZE - 2) {
     state->linebuf = qf_grow_linebuf(state, len);
   } else {
-    state->linebuf = (char *)IObuff;
+    state->linebuf = IObuff;
     state->linelen = len;
   }
 
-  STRLCPY(state->linebuf, TV_LIST_ITEM_TV(p_li)->vval.v_string,
-          state->linelen + 1);
+  xstrlcpy(state->linebuf, TV_LIST_ITEM_TV(p_li)->vval.v_string,
+           state->linelen + 1);
 
   state->p_li = TV_LIST_ITEM_NEXT(state->p_list, p_li);
   return QF_OK;
@@ -710,17 +726,17 @@ static int qf_get_next_buf_line(qfstate_T *state)
   if (state->buflnum > state->lnumlast) {
     return QF_END_OF_INPUT;
   }
-  char *p_buf = (char *)ml_get_buf(state->buf, state->buflnum, false);
+  char *p_buf = ml_get_buf(state->buf, state->buflnum, false);
   state->buflnum += 1;
 
-  size_t len = STRLEN(p_buf);
+  size_t len = strlen(p_buf);
   if (len > IOSIZE - 2) {
     state->linebuf = qf_grow_linebuf(state, len);
   } else {
-    state->linebuf = (char *)IObuff;
+    state->linebuf = IObuff;
     state->linelen = len;
   }
-  STRLCPY(state->linebuf, p_buf, state->linelen + 1);
+  xstrlcpy(state->linebuf, p_buf, state->linelen + 1);
 
   return QF_OK;
 }
@@ -730,7 +746,7 @@ static int qf_get_next_file_line(qfstate_T *state)
 {
 retry:
   errno = 0;
-  if (fgets((char *)IObuff, IOSIZE, state->fd) == NULL) {
+  if (fgets(IObuff, IOSIZE, state->fd) == NULL) {
     if (errno == EINTR) {
       goto retry;
     }
@@ -738,7 +754,7 @@ retry:
   }
 
   bool discard = false;
-  state->linelen = STRLEN(IObuff);
+  state->linelen = strlen(IObuff);
   if (state->linelen == IOSIZE - 1
       && !(IObuff[state->linelen - 1] == '\n')) {
     // The current line exceeds IObuff, continue reading using growbuf
@@ -761,7 +777,7 @@ retry:
         }
         break;
       }
-      state->linelen = STRLEN(state->growbuf + growbuflen);
+      state->linelen = strlen(state->growbuf + growbuflen);
       growbuflen += state->linelen;
       if (state->growbuf[growbuflen - 1] == '\n') {
         break;
@@ -780,13 +796,13 @@ retry:
       // The current line is longer than LINE_MAXLEN, continue reading but
       // discard everything until EOL or EOF is reached.
       errno = 0;
-      if (fgets((char *)IObuff, IOSIZE, state->fd) == NULL) {
+      if (fgets(IObuff, IOSIZE, state->fd) == NULL) {
         if (errno == EINTR) {
           continue;
         }
         break;
       }
-      if (STRLEN(IObuff) < IOSIZE - 1 || IObuff[IOSIZE - 2] == '\n') {
+      if (strlen(IObuff) < IOSIZE - 1 || IObuff[IOSIZE - 2] == '\n') {
         break;
       }
     }
@@ -794,15 +810,15 @@ retry:
     state->linebuf = state->growbuf;
     state->linelen = growbuflen;
   } else {
-    state->linebuf = (char *)IObuff;
+    state->linebuf = IObuff;
   }
 
   // Convert a line if it contains a non-ASCII character
-  if (state->vc.vc_type != CONV_NONE && has_non_ascii((char_u *)state->linebuf)) {
-    char *line = (char *)string_convert(&state->vc, (char_u *)state->linebuf, &state->linelen);
+  if (state->vc.vc_type != CONV_NONE && has_non_ascii(state->linebuf)) {
+    char *line = string_convert(&state->vc, state->linebuf, &state->linelen);
     if (line != NULL) {
       if (state->linelen < IOSIZE) {
-        STRLCPY(state->linebuf, line, state->linelen + 1);
+        xstrlcpy(state->linebuf, line, state->linelen + 1);
         xfree(line);
       } else {
         xfree(state->growbuf);
@@ -852,7 +868,7 @@ static int qf_get_nextline(qfstate_T *state)
 #endif
   }
 
-  remove_bom((char_u *)state->linebuf);
+  remove_bom(state->linebuf);
 
   return QF_OK;
 }
@@ -909,7 +925,7 @@ restofline:
   // match or no match.
   fields->valid = true;
   for (; fmt_ptr != NULL; fmt_ptr = fmt_ptr->next) {
-    idx = (char_u)fmt_ptr->prefix;
+    idx = (uint8_t)fmt_ptr->prefix;
     status = qf_parse_get_fields(linebuf, linelen, fmt_ptr, fields,
                                  qfl->qf_multiline, qfl->qf_multiscan,
                                  &tail);
@@ -1000,7 +1016,7 @@ static int qf_setup_state(qfstate_T *pstate, char *restrict enc, const char *res
 {
   pstate->vc.vc_type = CONV_NONE;
   if (enc != NULL && *enc != NUL) {
-    convert_setup(&pstate->vc, (char_u *)enc, p_enc);
+    convert_setup(&pstate->vc, enc, p_enc);
   }
 
   if (efile != NULL
@@ -1058,6 +1074,7 @@ static int qf_init_ext(qf_info_T *qi, int qf_idx, const char *restrict efile, bu
 {
   qfstate_T state = { 0 };
   qffields_T fields = { 0 };
+  qfline_T *old_last = NULL;
   static efm_T *fmt_first = NULL;
   static char *last_efm = NULL;
   int retval = -1;                      // default: return error flag
@@ -1071,7 +1088,6 @@ static int qf_init_ext(qf_info_T *qi, int qf_idx, const char *restrict efile, bu
   }
 
   qf_list_T *qfl;
-  qfline_T *old_last = NULL;
   bool adding = false;
   if (newlist || qf_idx == qi->qf_listcount) {
     // make place for a new list
@@ -1091,14 +1107,14 @@ static int qf_init_ext(qf_info_T *qi, int qf_idx, const char *restrict efile, bu
 
   // Use the local value of 'errorformat' if it's set.
   if (errorformat == p_efm && tv == NULL && buf && *buf->b_p_efm != NUL) {
-    efm = (char *)buf->b_p_efm;
+    efm = buf->b_p_efm;
   } else {
     efm = errorformat;
   }
 
   // If the errorformat didn't change between calls, then reuse the previously
   // parsed values.
-  if (last_efm == NULL || (STRCMP(last_efm, efm) != 0)) {
+  if (last_efm == NULL || (strcmp(last_efm, efm) != 0)) {
     // free the previously parsed data
     XFREE_CLEAR(last_efm);
     free_efm_list(&fmt_first);
@@ -1174,13 +1190,15 @@ static void qf_store_title(qf_list_T *qfl, const char *title)
 {
   XFREE_CLEAR(qfl->qf_title);
 
-  if (title != NULL) {
-    size_t len = STRLEN(title) + 1;
-    char *p = xmallocz(len);
-
-    qfl->qf_title = p;
-    STRLCPY(p, title, len + 1);
+  if (title == NULL) {
+    return;
   }
+
+  size_t len = strlen(title) + 1;
+  char *p = xmallocz(len);
+
+  qfl->qf_title = p;
+  xstrlcpy(p, title, len + 1);
 }
 
 /// The title of a quickfix/location list is set, by default, to the command
@@ -1242,15 +1260,15 @@ static int qf_parse_fmt_f(regmatch_T *rmp, int midx, qffields_T *fields, int pre
   }
 
   // Expand ~/file and $HOME/file to full path.
-  char c = (char)(*rmp->endp[midx]);
+  char c = *rmp->endp[midx];
   *rmp->endp[midx] = NUL;
-  expand_env(rmp->startp[midx], (char_u *)fields->namebuf, CMDBUFFSIZE);
-  *rmp->endp[midx] = (char_u)c;
+  expand_env(rmp->startp[midx], fields->namebuf, CMDBUFFSIZE);
+  *rmp->endp[midx] = c;
 
   // For separate filename patterns (%O, %P and %Q), the specified file
   // should exist.
   if (vim_strchr("OPQ", prefix) != NULL
-      && !os_path_exists((char_u *)fields->namebuf)) {
+      && !os_path_exists(fields->namebuf)) {
     return QF_FAIL;
   }
 
@@ -1264,7 +1282,7 @@ static int qf_parse_fmt_n(regmatch_T *rmp, int midx, qffields_T *fields)
   if (rmp->startp[midx] == NULL) {
     return QF_FAIL;
   }
-  fields->enr = (int)atol((char *)rmp->startp[midx]);
+  fields->enr = (int)atol(rmp->startp[midx]);
   return QF_OK;
 }
 
@@ -1275,7 +1293,7 @@ static int qf_parse_fmt_l(regmatch_T *rmp, int midx, qffields_T *fields)
   if (rmp->startp[midx] == NULL) {
     return QF_FAIL;
   }
-  fields->lnum = (linenr_T)atol((char *)rmp->startp[midx]);
+  fields->lnum = (linenr_T)atol(rmp->startp[midx]);
   return QF_OK;
 }
 
@@ -1286,7 +1304,7 @@ static int qf_parse_fmt_e(regmatch_T *rmp, int midx, qffields_T *fields)
   if (rmp->startp[midx] == NULL) {
     return QF_FAIL;
   }
-  fields->end_lnum = (linenr_T)atol((char *)rmp->startp[midx]);
+  fields->end_lnum = (linenr_T)atol(rmp->startp[midx]);
   return QF_OK;
 }
 
@@ -1297,7 +1315,7 @@ static int qf_parse_fmt_c(regmatch_T *rmp, int midx, qffields_T *fields)
   if (rmp->startp[midx] == NULL) {
     return QF_FAIL;
   }
-  fields->col = (int)atol((char *)rmp->startp[midx]);
+  fields->col = (int)atol(rmp->startp[midx]);
   return QF_OK;
 }
 
@@ -1308,7 +1326,7 @@ static int qf_parse_fmt_k(regmatch_T *rmp, int midx, qffields_T *fields)
   if (rmp->startp[midx] == NULL) {
     return QF_FAIL;
   }
-  fields->end_col = (int)atol((char *)rmp->startp[midx]);
+  fields->end_col = (int)atol(rmp->startp[midx]);
   return QF_OK;
 }
 
@@ -1319,13 +1337,13 @@ static int qf_parse_fmt_t(regmatch_T *rmp, int midx, qffields_T *fields)
   if (rmp->startp[midx] == NULL) {
     return QF_FAIL;
   }
-  fields->type = (char)(*rmp->startp[midx]);
+  fields->type = *rmp->startp[midx];
   return QF_OK;
 }
 
-/// Parse the match for '%+' format pattern. The whole matching line is included
-/// in the error string.  Return the matched line in "fields->errmsg".
-static void qf_parse_fmt_plus(const char *linebuf, size_t linelen, qffields_T *fields)
+/// Copy a non-error line into the error string.  Return the matched line in
+/// "fields->errmsg".
+static int copy_nonerror_line(const char *linebuf, size_t linelen, qffields_T *fields)
   FUNC_ATTR_NONNULL_ALL
 {
   if (linelen >= fields->errmsglen) {
@@ -1333,7 +1351,10 @@ static void qf_parse_fmt_plus(const char *linebuf, size_t linelen, qffields_T *f
     fields->errmsg = xrealloc(fields->errmsg, linelen + 1);
     fields->errmsglen = linelen + 1;
   }
-  STRLCPY(fields->errmsg, linebuf, linelen + 1);
+  // copy whole line to error message
+  xstrlcpy(fields->errmsg, linebuf, linelen + 1);
+
+  return QF_OK;
 }
 
 /// Parse the match for error message ('%m') pattern in regmatch.
@@ -1349,7 +1370,7 @@ static int qf_parse_fmt_m(regmatch_T *rmp, int midx, qffields_T *fields)
     fields->errmsg = xrealloc(fields->errmsg, len + 1);
     fields->errmsglen = len + 1;
   }
-  STRLCPY(fields->errmsg, rmp->startp[midx], len + 1);
+  xstrlcpy(fields->errmsg, rmp->startp[midx], len + 1);
   return QF_OK;
 }
 
@@ -1360,7 +1381,7 @@ static int qf_parse_fmt_r(regmatch_T *rmp, int midx, char **tail)
   if (rmp->startp[midx] == NULL) {
     return QF_FAIL;
   }
-  *tail = (char *)rmp->startp[midx];
+  *tail = rmp->startp[midx];
   return QF_OK;
 }
 
@@ -1372,7 +1393,7 @@ static int qf_parse_fmt_p(regmatch_T *rmp, int midx, qffields_T *fields)
     return QF_FAIL;
   }
   fields->col = 0;
-  for (char *match_ptr = (char *)rmp->startp[midx]; (char_u *)match_ptr != rmp->endp[midx];
+  for (char *match_ptr = rmp->startp[midx]; match_ptr != rmp->endp[midx];
        match_ptr++) {
     fields->col++;
     if (*match_ptr == TAB) {
@@ -1392,7 +1413,7 @@ static int qf_parse_fmt_v(regmatch_T *rmp, int midx, qffields_T *fields)
   if (rmp->startp[midx] == NULL) {
     return QF_FAIL;
   }
-  fields->col = (int)atol((char *)rmp->startp[midx]);
+  fields->col = (int)atol(rmp->startp[midx]);
   fields->use_viscol = true;
   return QF_OK;
 }
@@ -1409,7 +1430,7 @@ static int qf_parse_fmt_s(regmatch_T *rmp, int midx, qffields_T *fields)
     len = CMDBUFFSIZE - 5;
   }
   STRCPY(fields->pattern, "^\\V");
-  STRLCAT(fields->pattern, rmp->startp[midx], len + 4);
+  xstrlcat(fields->pattern, rmp->startp[midx], len + 4);
   fields->pattern[len + 3] = '\\';
   fields->pattern[len + 4] = '$';
   fields->pattern[len + 5] = NUL;
@@ -1424,11 +1445,11 @@ static int qf_parse_fmt_o(regmatch_T *rmp, int midx, qffields_T *fields)
     return QF_FAIL;
   }
   size_t len = (size_t)(rmp->endp[midx] - rmp->startp[midx]);
-  size_t dsize = STRLEN(fields->module) + len + 1;
+  size_t dsize = strlen(fields->module) + len + 1;
   if (dsize > CMDBUFFSIZE) {
     dsize = CMDBUFFSIZE;
   }
-  STRLCAT(fields->module, rmp->startp[midx], dsize);
+  xstrlcat(fields->module, rmp->startp[midx], dsize);
   return QF_OK;
 }
 
@@ -1464,7 +1485,7 @@ static int qf_parse_match(char *linebuf, size_t linelen, efm_T *fmt_ptr, regmatc
   if ((idx == 'C' || idx == 'Z') && !qf_multiline) {
     return QF_FAIL;
   }
-  if (vim_strchr("EWIN", idx) != NULL) {
+  if (vim_strchr("EWIN", (uint8_t)idx) != NULL) {
     fields->type = idx;
   } else {
     fields->type = 0;
@@ -1480,7 +1501,7 @@ static int qf_parse_match(char *linebuf, size_t linelen, efm_T *fmt_ptr, regmatc
       status = qf_parse_fmt_f(regmatch, midx, fields, idx);
     } else if (i == FMT_PATTERN_M) {
       if (fmt_ptr->flags == '+' && !qf_multiscan) {  // %+
-        qf_parse_fmt_plus(linebuf, linelen, fields);
+        status = copy_nonerror_line(linebuf, linelen, fields);
       } else if (midx > 0) {  // %m
         status = qf_parse_fmt_m(regmatch, midx, fields);
       }
@@ -1505,7 +1526,7 @@ static int qf_parse_match(char *linebuf, size_t linelen, efm_T *fmt_ptr, regmatc
 static int qf_parse_get_fields(char *linebuf, size_t linelen, efm_T *fmt_ptr, qffields_T *fields,
                                int qf_multiline, int qf_multiscan, char **tail)
 {
-  if (qf_multiscan && vim_strchr("OPQ", fmt_ptr->prefix) == NULL) {
+  if (qf_multiscan && vim_strchr("OPQ", (uint8_t)fmt_ptr->prefix) == NULL) {
     return QF_FAIL;
   }
 
@@ -1564,7 +1585,7 @@ static int qf_parse_dir_pfx(int idx, qffields_T *fields, qf_list_T *qfl)
 static int qf_parse_file_pfx(int idx, qffields_T *fields, qf_list_T *qfl, char *tail)
 {
   fields->valid = false;
-  if (*fields->namebuf == NUL || os_path_exists((char_u *)fields->namebuf)) {
+  if (*fields->namebuf == NUL || os_path_exists(fields->namebuf)) {
     if (*fields->namebuf && idx == 'P') {
       qfl->qf_currfile = qf_push_dir(fields->namebuf, &qfl->qf_file_stack, true);
     } else if (idx == 'Q') {
@@ -1588,15 +1609,8 @@ static int qf_parse_line_nomatch(char *linebuf, size_t linelen, qffields_T *fiel
   fields->namebuf[0] = NUL;   // no match found, remove file name
   fields->lnum = 0;           // don't jump to this line
   fields->valid = false;
-  if (linelen >= fields->errmsglen) {
-    // linelen + null terminator
-    fields->errmsg = xrealloc(fields->errmsg, linelen + 1);
-    fields->errmsglen = linelen + 1;
-  }
-  // copy whole line to error message
-  STRLCPY(fields->errmsg, linebuf, linelen + 1);
 
-  return QF_OK;
+  return copy_nonerror_line(linebuf, linelen, fields);
 }
 
 /// Parse multi-line error format prefixes (%C and %Z)
@@ -1609,8 +1623,8 @@ static int qf_parse_multiline_pfx(int idx, qf_list_T *qfl, qffields_T *fields)
       return QF_FAIL;
     }
     if (*fields->errmsg) {
-      size_t textlen = STRLEN(qfprev->qf_text);
-      size_t errlen  = STRLEN(fields->errmsg);
+      size_t textlen = strlen(qfprev->qf_text);
+      size_t errlen  = strlen(fields->errmsg);
       qfprev->qf_text = xrealloc(qfprev->qf_text, textlen + errlen + 2);
       qfprev->qf_text[textlen] = '\n';
       STRCPY(qfprev->qf_text + textlen + 1, fields->errmsg);
@@ -1672,14 +1686,16 @@ int qf_stack_get_bufnr(void)
 static void wipe_qf_buffer(qf_info_T *qi)
   FUNC_ATTR_NONNULL_ALL
 {
-  if (qi->qf_bufnr != INVALID_QFBUFNR) {
-    buf_T *const qfbuf = buflist_findnr(qi->qf_bufnr);
-    if (qfbuf != NULL && qfbuf->b_nwindows == 0) {
-      // If the quickfix buffer is not loaded in any window, then
-      // wipe the buffer.
-      close_buffer(NULL, qfbuf, DOBUF_WIPE, false, false);
-      qi->qf_bufnr = INVALID_QFBUFNR;
-    }
+  if (qi->qf_bufnr == INVALID_QFBUFNR) {
+    return;
+  }
+
+  buf_T *const qfbuf = buflist_findnr(qi->qf_bufnr);
+  if (qfbuf != NULL && qfbuf->b_nwindows == 0) {
+    // If the quickfix buffer is not loaded in any window, then
+    // wipe the buffer.
+    close_buffer(NULL, qfbuf, DOBUF_WIPE, false, false);
+    qi->qf_bufnr = INVALID_QFBUFNR;
   }
 }
 
@@ -1790,7 +1806,7 @@ void check_quickfix_busy(void)
 /// @param  type     type character
 /// @param  valid    valid entry
 ///
-/// @returns QF_OK or QF_FAIL.
+/// @return  QF_OK on success or QF_FAIL on failure.
 static int qf_add_entry(qf_list_T *qfl, char *dir, char *fname, char *module, int bufnum,
                         char *mesg, linenr_T lnum, linenr_T end_lnum, int col, int end_col,
                         char vis_col, char *pattern, int nr, char type, char valid)
@@ -1891,7 +1907,7 @@ static qf_info_T *ll_get_or_alloc_list(win_T *wp)
 /// Get the quickfix/location list stack to use for the specified Ex command.
 /// For a location list command, returns the stack for the current window.  If
 /// the location list is not found, then returns NULL and prints an error
-/// message if 'print_emsg' is TRUE.
+/// message if 'print_emsg' is true.
 static qf_info_T *qf_cmd_get_stack(exarg_T *eap, int print_emsg)
 {
   qf_info_T *qi = &ql_info;
@@ -2063,13 +2079,13 @@ static int qf_get_fnum(qf_list_T *qfl, char *directory, char *fname)
   }
   slash_adjust(fname);
 #endif
-  if (directory != NULL && !vim_isAbsName((char_u *)fname)) {
+  if (directory != NULL && !vim_isAbsName(fname)) {
     ptr = concat_fnames(directory, fname, true);
     // Here we check if the file really exists.
     // This should normally be true, but if make works without
     // "leaving directory"-messages we might have missed a
     // directory change.
-    if (!os_path_exists((char_u *)ptr)) {
+    if (!os_path_exists(ptr)) {
       xfree(ptr);
       directory = qf_guess_filepath(qfl, fname);
       if (directory) {
@@ -2085,7 +2101,7 @@ static int qf_get_fnum(qf_list_T *qfl, char *directory, char *fname)
   }
 
   if (qf_last_bufname != NULL
-      && STRCMP(bufname, qf_last_bufname) == 0
+      && strcmp(bufname, qf_last_bufname) == 0
       && bufref_valid(&qf_last_bufref)) {
     buf = qf_last_bufref.br_buf;
     xfree(ptr);
@@ -2116,7 +2132,7 @@ static char *qf_push_dir(char *dirbuf, struct dir_stack_T **stackptr, bool is_fi
   *stackptr = ds_new;
 
   // store directory on the stack
-  if (vim_isAbsName((char_u *)dirbuf)
+  if (vim_isAbsName(dirbuf)
       || (*stackptr)->next == NULL
       || is_file_stack) {
     (*stackptr)->dirname = xstrdup(dirbuf);
@@ -2129,7 +2145,7 @@ static char *qf_push_dir(char *dirbuf, struct dir_stack_T **stackptr, bool is_fi
     while (ds_new) {
       xfree((*stackptr)->dirname);
       (*stackptr)->dirname = concat_fnames(ds_new->dirname, dirbuf, true);
-      if (os_isdir((char_u *)(*stackptr)->dirname)) {
+      if (os_isdir((*stackptr)->dirname)) {
         break;
       }
 
@@ -2153,12 +2169,11 @@ static char *qf_push_dir(char *dirbuf, struct dir_stack_T **stackptr, bool is_fi
 
   if ((*stackptr)->dirname != NULL) {
     return (*stackptr)->dirname;
-  } else {
-    ds_ptr = *stackptr;
-    *stackptr = (*stackptr)->next;
-    xfree(ds_ptr);
-    return NULL;
   }
+  ds_ptr = *stackptr;
+  *stackptr = (*stackptr)->next;
+  xfree(ds_ptr);
+  return NULL;
 }
 
 // pop dirbuf from the directory stack and return previous directory or NULL if
@@ -2223,7 +2238,7 @@ static char *qf_guess_filepath(qf_list_T *qfl, char *filename)
     xfree(fullname);
     fullname = concat_fnames(ds_ptr->dirname, filename, true);
 
-    if (os_path_exists((char_u *)fullname)) {
+    if (os_path_exists(fullname)) {
       break;
     }
 
@@ -2511,7 +2526,7 @@ static win_T *qf_find_win_with_normal_buf(void)
 }
 
 // Go to a window in any tabpage containing the specified file.  Returns true
-// if successfully jumped to the window. Otherwise returns FALSE.
+// if successfully jumped to the window. Otherwise returns false.
 static bool qf_goto_tabwin_with_file(int fnum)
 {
   FOR_ALL_TAB_WINDOWS(tp, wp) {
@@ -2686,6 +2701,10 @@ static int qf_jump_to_usable_window(int qf_fnum, bool newwin, int *opened_window
 }
 
 /// Edit the selected file or help file.
+/// @return  OK if successfully edited the file.
+///          FAIL on failing to open the buffer.
+///          QF_ABORT if the quickfix/location list was freed by an autocmd
+///          when opening the buffer.
 static int qf_jump_edit_buffer(qf_info_T *qi, qfline_T *qf_ptr, int forceit, int prev_winid,
                                int *opened_window)
 {
@@ -2702,11 +2721,10 @@ static int qf_jump_edit_buffer(qf_info_T *qi, qfline_T *qf_ptr, int forceit, int
     if (!can_abandon(curbuf, forceit)) {
       no_write_message();
       return FAIL;
-    } else {
-      retval = do_ecmd(qf_ptr->qf_fnum, NULL, NULL, NULL, (linenr_T)1,
-                       ECMD_HIDE + ECMD_SET_HELP,
-                       prev_winid == curwin->handle ? curwin : NULL);
     }
+    retval = do_ecmd(qf_ptr->qf_fnum, NULL, NULL, NULL, (linenr_T)1,
+                     ECMD_HIDE + ECMD_SET_HELP,
+                     prev_winid == curwin->handle ? curwin : NULL);
   } else {
     retval = buflist_getfile(qf_ptr->qf_fnum, (linenr_T)1,
                              GETF_SETMARK | GETF_SWITCH, forceit);
@@ -2719,13 +2737,13 @@ static int qf_jump_edit_buffer(qf_info_T *qi, qfline_T *qf_ptr, int forceit, int
     if (wp == NULL && curwin->w_llist != qi) {
       emsg(_("E924: Current window was closed"));
       *opened_window = false;
-      return NOTDONE;
+      return QF_ABORT;
     }
   }
 
   if (qfl_type == QFLT_QUICKFIX && !qflist_valid(NULL, save_qfid)) {
     emsg(_(e_current_quickfix_list_was_changed));
-    return NOTDONE;
+    return QF_ABORT;
   }
 
   if (old_qf_curlist != qi->qf_curlist  // -V560
@@ -2736,7 +2754,7 @@ static int qf_jump_edit_buffer(qf_info_T *qi, qfline_T *qf_ptr, int forceit, int
     } else {
       emsg(_(e_current_location_list_was_changed));
     }
-    return NOTDONE;
+    return QF_ABORT;
   }
 
   return retval;
@@ -2771,7 +2789,7 @@ static void qf_jump_goto_line(linenr_T qf_lnum, int qf_col, char qf_viscol, char
     // Move the cursor to the first line in the buffer
     pos_T save_cursor = curwin->w_cursor;
     curwin->w_cursor.lnum = 0;
-    if (!do_search(NULL, '/', '/', (char_u *)qf_pattern, (long)1, SEARCH_KEEP, NULL)) {
+    if (!do_search(NULL, '/', '/', qf_pattern, (long)1, SEARCH_KEEP, NULL)) {
       curwin->w_cursor = save_cursor;
     }
   }
@@ -2784,15 +2802,18 @@ static void qf_jump_print_msg(qf_info_T *qi, int qf_index, qfline_T *qf_ptr, buf
   // Update the screen before showing the message, unless the screen
   // scrolled up.
   if (!msg_scrolled) {
-    update_topline_redraw();
+    update_topline(curwin);
+    if (must_redraw) {
+      update_screen();
+    }
   }
-  snprintf((char *)IObuff, IOSIZE, _("(%d of %d)%s%s: "), qf_index,
+  snprintf(IObuff, IOSIZE, _("(%d of %d)%s%s: "), qf_index,
            qf_get_curlist(qi)->qf_count,
            qf_ptr->qf_cleared ? _(" (line deleted)") : "",
            qf_types(qf_ptr->qf_type, qf_ptr->qf_nr));
   // Add the message, skipping leading whitespace and newlines.
-  int len = (int)STRLEN(IObuff);
-  qf_fmt_text(skipwhite(qf_ptr->qf_text), (char *)IObuff + len, IOSIZE - len);
+  int len = (int)strlen(IObuff);
+  qf_fmt_text(skipwhite(qf_ptr->qf_text), IObuff + len, IOSIZE - len);
 
   // Output the message.  Overwrite to avoid scrolling when the 'O'
   // flag is present in 'shortmess'; But when not jumping, print the
@@ -2804,16 +2825,17 @@ static void qf_jump_print_msg(qf_info_T *qi, int qf_index, qfline_T *qf_ptr, buf
     msg_scroll = false;
   }
   msg_ext_set_kind("quickfix");
-  msg_attr_keep((char *)IObuff, 0, true, false);
+  msg_attr_keep(IObuff, 0, true, false);
   msg_scroll = (int)i;
 }
 
 /// Find a usable window for opening a file from the quickfix/location list. If
 /// a window is not found then open a new window. If 'newwin' is true, then open
 /// a new window.
-/// Returns OK if successfully jumped or opened a window. Returns FAIL if not
-/// able to jump/open a window.  Returns NOTDONE if a file is not associated
-/// with the entry.
+/// @return  OK if successfully jumped or opened a window.
+///          FAIL if not able to jump/open a window.
+///          NOTDONE if a file is not associated with the entry.
+///          QF_ABORT if the quickfix/location list was modified by an autocmd.
 static int qf_jump_open_window(qf_info_T *qi, qfline_T *qf_ptr, bool newwin, int *opened_window)
 {
   qf_list_T *qfl = qf_get_curlist(qi);
@@ -2835,7 +2857,7 @@ static int qf_jump_open_window(qf_info_T *qi, qfline_T *qf_ptr, bool newwin, int
     } else {
       emsg(_(e_current_location_list_was_changed));
     }
-    return FAIL;
+    return QF_ABORT;
   }
 
   // If currently in the quickfix window, find another window to show the
@@ -2860,7 +2882,7 @@ static int qf_jump_open_window(qf_info_T *qi, qfline_T *qf_ptr, bool newwin, int
     } else {
       emsg(_(e_current_location_list_was_changed));
     }
-    return FAIL;
+    return QF_ABORT;
   }
 
   return OK;
@@ -2869,9 +2891,9 @@ static int qf_jump_open_window(qf_info_T *qi, qfline_T *qf_ptr, bool newwin, int
 /// Edit a selected file from the quickfix/location list and jump to a
 /// particular line/column, adjust the folds and display a message about the
 /// jump.
-/// Returns OK on success and FAIL on failing to open the file/buffer.  Returns
-/// NOTDONE if the quickfix/location list is freed by an autocmd when opening
-/// the file.
+/// @return  OK on success and FAIL on failing to open the file/buffer.
+///          QF_ABORT if the quickfix/location list is freed by an autocmd when opening
+///          the file.
 static int qf_jump_to_buffer(qf_info_T *qi, int qf_index, qfline_T *qf_ptr, int forceit,
                              int prev_winid, int *opened_window, int openfold, int print_message)
 {
@@ -2923,7 +2945,7 @@ void qf_jump(qf_info_T *qi, int dir, int errornr, int forceit)
 // If 'newwin' is true, then open the file in a new window.
 static void qf_jump_newwin(qf_info_T *qi, int dir, int errornr, int forceit, bool newwin)
 {
-  char *old_swb = (char *)p_swb;
+  char *old_swb = p_swb;
   unsigned old_swb_flags = swb_flags;
   const bool old_KeyTyped = KeyTyped;           // getting file may reset it
 
@@ -2932,7 +2954,7 @@ static void qf_jump_newwin(qf_info_T *qi, int dir, int errornr, int forceit, boo
   }
 
   if (qf_stack_empty(qi) || qf_list_empty(qf_get_curlist(qi))) {
-    emsg(_(e_quickfix));
+    emsg(_(e_no_errors));
     return;
   }
 
@@ -2965,14 +2987,19 @@ static void qf_jump_newwin(qf_info_T *qi, int dir, int errornr, int forceit, boo
   if (retval == FAIL) {
     goto failed;
   }
+  if (retval == QF_ABORT) {
+    qi = NULL;
+    qf_ptr = NULL;
+    goto theend;
+  }
   if (retval == NOTDONE) {
     goto theend;
   }
 
   retval = qf_jump_to_buffer(qi, qf_index, qf_ptr, forceit, prev_winid,
                              &opened_window, old_KeyTyped, print_message);
-  if (retval == NOTDONE) {
-    // Quickfix/location list is freed by an autocmd
+  if (retval == QF_ABORT) {
+    // Quickfix/location list was modified by an autocmd
     qi = NULL;
     qf_ptr = NULL;
   }
@@ -2994,10 +3021,10 @@ theend:
     qfl->qf_ptr = qf_ptr;
     qfl->qf_index = qf_index;
   }
-  if (p_swb != (char_u *)old_swb && p_swb == empty_option) {
+  if (p_swb != old_swb && p_swb == empty_option) {
     // Restore old 'switchbuf' value, but not when an autocommand or
     // modeline has changed the value.
-    p_swb = (char_u *)old_swb;
+    p_swb = old_swb;
     swb_flags = old_swb_flags;
   }
   decr_quickfix_busy();
@@ -3016,7 +3043,7 @@ static void qf_list_entry(qfline_T *qfp, int qf_idx, bool cursel)
 {
   char *fname = NULL;
   if (qfp->qf_module != NULL && *qfp->qf_module != NUL) {
-    vim_snprintf((char *)IObuff, IOSIZE, "%2d %s", qf_idx, qfp->qf_module);
+    vim_snprintf(IObuff, IOSIZE, "%2d %s", qf_idx, qfp->qf_module);
   } else {
     buf_T *buf;
     if (qfp->qf_fnum != 0
@@ -3027,9 +3054,9 @@ static void qf_list_entry(qfline_T *qfp, int qf_idx, bool cursel)
       }
     }
     if (fname == NULL) {
-      snprintf((char *)IObuff, IOSIZE, "%2d", qf_idx);
+      snprintf(IObuff, IOSIZE, "%2d", qf_idx);
     } else {
-      vim_snprintf((char *)IObuff, IOSIZE, "%2d %s", qf_idx, fname);
+      vim_snprintf(IObuff, IOSIZE, "%2d %s", qf_idx, fname);
     }
   }
 
@@ -3038,16 +3065,16 @@ static void qf_list_entry(qfline_T *qfp, int qf_idx, bool cursel)
   // text of the entry.
   bool filter_entry = true;
   if (qfp->qf_module != NULL && *qfp->qf_module != NUL) {
-    filter_entry &= message_filtered((char_u *)qfp->qf_module);
+    filter_entry &= message_filtered(qfp->qf_module);
   }
   if (filter_entry && fname != NULL) {
-    filter_entry &= message_filtered((char_u *)fname);
+    filter_entry &= message_filtered(fname);
   }
   if (filter_entry && qfp->qf_pattern != NULL) {
-    filter_entry &= message_filtered((char_u *)qfp->qf_pattern);
+    filter_entry &= message_filtered(qfp->qf_pattern);
   }
   if (filter_entry) {
-    filter_entry &= message_filtered((char_u *)qfp->qf_text);
+    filter_entry &= message_filtered(qfp->qf_text);
   }
   if (filter_entry) {
     return;
@@ -3062,21 +3089,21 @@ static void qf_list_entry(qfline_T *qfp, int qf_idx, bool cursel)
   if (qfp->qf_lnum == 0) {
     IObuff[0] = NUL;
   } else {
-    qf_range_text(qfp, (char *)IObuff, IOSIZE);
+    qf_range_text(qfp, IObuff, IOSIZE);
   }
-  vim_snprintf((char *)IObuff + STRLEN(IObuff), IOSIZE, "%s", qf_types(qfp->qf_type, qfp->qf_nr));
+  vim_snprintf(IObuff + strlen(IObuff), IOSIZE, "%s", qf_types(qfp->qf_type, qfp->qf_nr));
   msg_puts_attr((const char *)IObuff, qfLineAttr);
   msg_puts_attr(":", qfSepAttr);
   if (qfp->qf_pattern != NULL) {
-    qf_fmt_text(qfp->qf_pattern, (char *)IObuff, IOSIZE);
+    qf_fmt_text(qfp->qf_pattern, IObuff, IOSIZE);
     msg_puts((const char *)IObuff);
     msg_puts_attr(":", qfSepAttr);
   }
   msg_puts(" ");
 
-  char_u *tbuf = IObuff;
+  char *tbuf = IObuff;
   size_t tbuflen = IOSIZE;
-  size_t len = STRLEN(qfp->qf_text) + 3;
+  size_t len = strlen(qfp->qf_text) + 3;
 
   if (len > IOSIZE) {
     tbuf = xmalloc(len);
@@ -3088,14 +3115,12 @@ static void qf_list_entry(qfline_T *qfp, int qf_idx, bool cursel)
   // with ^^^^.
   qf_fmt_text((fname != NULL || qfp->qf_lnum != 0)
               ? skipwhite(qfp->qf_text) : qfp->qf_text,
-              (char *)tbuf, (int)tbuflen);
+              tbuf, (int)tbuflen);
   msg_prt_line(tbuf, false);
 
   if (tbuf != IObuff) {
     xfree(tbuf);
   }
-
-  ui_flush();  // show one line at a time
 }
 
 // ":clist": list all errors
@@ -3111,7 +3136,7 @@ void qf_list(exarg_T *eap)
   }
 
   if (qf_stack_empty(qi) || qf_list_empty(qf_get_curlist(qi))) {
-    emsg(_(e_quickfix));
+    emsg(_(e_no_errors));
     return;
   }
 
@@ -3147,15 +3172,15 @@ void qf_list(exarg_T *eap)
 
   // Get the attributes for the different quickfix highlight items.  Note
   // that this depends on syntax items defined in the qf.vim syntax file
-  qfFileAttr = syn_name2attr((char_u *)"qfFileName");
+  qfFileAttr = syn_name2attr("qfFileName");
   if (qfFileAttr == 0) {
     qfFileAttr = HL_ATTR(HLF_D);
   }
-  qfSepAttr = syn_name2attr((char_u *)"qfSeparator");
+  qfSepAttr = syn_name2attr("qfSeparator");
   if (qfSepAttr == 0) {
     qfSepAttr = HL_ATTR(HLF_D);
   }
-  qfLineAttr = syn_name2attr((char_u *)"qfLineNr");
+  qfLineAttr = syn_name2attr("qfLineNr");
   if (qfLineAttr == 0) {
     qfLineAttr = HL_ATTR(HLF_N);
   }
@@ -3180,7 +3205,7 @@ static void qf_fmt_text(const char *restrict text, char *restrict buf, int bufsi
   int i;
   const char *p = (char *)text;
 
-  for (i = 0; *p != NUL && i < bufsize - 1; ++i) {
+  for (i = 0; *p != NUL && i < bufsize - 1; i++) {
     if (*p == '\n') {
       buf[i] = ' ';
       while (*++p != NUL) {
@@ -3200,18 +3225,18 @@ static void qf_fmt_text(const char *restrict text, char *restrict buf, int bufsi
 static void qf_range_text(const qfline_T *qfp, char *buf, int bufsize)
 {
   vim_snprintf(buf, (size_t)bufsize, "%" PRIdLINENR, qfp->qf_lnum);
-  int len = (int)STRLEN(buf);
+  int len = (int)strlen(buf);
 
   if (qfp->qf_end_lnum > 0 && qfp->qf_lnum != qfp->qf_end_lnum) {
     vim_snprintf(buf + len, (size_t)(bufsize - len), "-%" PRIdLINENR, qfp->qf_end_lnum);
-    len += (int)STRLEN(buf + len);
+    len += (int)strlen(buf + len);
   }
   if (qfp->qf_col > 0) {
     vim_snprintf(buf + len, (size_t)(bufsize - len), " col %d", qfp->qf_col);
-    len += (int)STRLEN(buf + len);
+    len += (int)strlen(buf + len);
     if (qfp->qf_end_col > 0 && qfp->qf_col != qfp->qf_end_col) {
       vim_snprintf(buf + len, (size_t)(bufsize - len), "-%d", qfp->qf_end_col);
-      len += (int)STRLEN(buf + len);
+      len += (int)strlen(buf + len);
     }
   }
   buf[len] = NUL;
@@ -3232,13 +3257,13 @@ static void qf_msg(qf_info_T *qi, int which, char *lead)
                count);
 
   if (title != NULL) {
-    size_t len = STRLEN(buf);
+    size_t len = strlen(buf);
 
     if (len < 34) {
       memset(buf + len, ' ', 34 - len);
       buf[34] = NUL;
     }
-    STRLCAT(buf, title, IOSIZE);
+    xstrlcat(buf, title, IOSIZE);
   }
   trunc_string(buf, buf, Columns - 1, IOSIZE);
   msg(buf);
@@ -3263,13 +3288,13 @@ void qf_age(exarg_T *eap)
         emsg(_("E380: At bottom of quickfix stack"));
         break;
       }
-      --qi->qf_curlist;
+      qi->qf_curlist--;
     } else {
       if (qi->qf_curlist >= qi->qf_listcount - 1) {
         emsg(_("E381: At top of quickfix stack"));
         break;
       }
-      ++qi->qf_curlist;
+      qi->qf_curlist++;
     }
   }
   qf_msg(qi, qi->qf_curlist, "");
@@ -3393,7 +3418,7 @@ bool qf_mark_adjust(win_T *wp, linenr_T line1, linenr_T line2, linenr_T amount,
           found_one = true;
           if (qfp->qf_lnum >= line1 && qfp->qf_lnum <= line2) {
             if (amount == MAXLNUM) {
-              qfp->qf_cleared = TRUE;
+              qfp->qf_cleared = true;
             } else {
               qfp->qf_lnum += amount;
             }
@@ -3460,14 +3485,12 @@ void qf_view_result(bool split)
 {
   qf_info_T *qi = &ql_info;
 
-  if (!bt_quickfix(curbuf)) {
-    return;
-  }
   if (IS_LL_WINDOW(curwin)) {
     qi = GET_LOC_LIST(curwin);
   }
+
   if (qf_list_empty(qf_get_curlist(qi))) {
-    emsg(_(e_quickfix));
+    emsg(_(e_no_errors));
     return;
   }
 
@@ -3558,12 +3581,12 @@ static int qf_goto_cwindow(const qf_info_T *qi, bool resize, int sz, bool vertsp
 static void qf_set_cwindow_options(void)
 {
   // switch off 'swapfile'
-  set_option_value("swf", 0L, NULL, OPT_LOCAL);
-  set_option_value("bt", 0L, "quickfix", OPT_LOCAL);
-  set_option_value("bh", 0L, "hide", OPT_LOCAL);
+  set_option_value_give_err("swf", 0L, NULL, OPT_LOCAL);
+  set_option_value_give_err("bt", 0L, "quickfix", OPT_LOCAL);
+  set_option_value_give_err("bh", 0L, "hide", OPT_LOCAL);
   RESET_BINDING(curwin);
   curwin->w_p_diff = false;
-  set_option_value("fdm", 0L, "manual", OPT_LOCAL);
+  set_option_value_give_err("fdm", 0L, "manual", OPT_LOCAL);
 }
 
 // Open a new quickfix or location list window, load the quickfix buffer and
@@ -3710,7 +3733,7 @@ static void qf_win_goto(win_T *win, linenr_T lnum)
   curwin->w_cursor.coladd = 0;
   curwin->w_curswant = 0;
   update_topline(curwin);              // scroll to show the line
-  redraw_later(curwin, VALID);
+  redraw_later(curwin, UPD_VALID);
   curwin->w_redr_status = true;  // update ruler
   curwin = old_curwin;
   curbuf = curwin->w_buffer;
@@ -3747,7 +3770,7 @@ linenr_T qf_current_entry(win_T *wp)
 }
 
 /// Update the cursor position in the quickfix window to the current error.
-/// Return TRUE if there is a quickfix window.
+/// Return true if there is a quickfix window.
 ///
 /// @param old_qf_index  previous qf_index or zero
 static bool qf_win_pos_update(qf_info_T *qi, int old_qf_index)
@@ -3831,10 +3854,11 @@ static buf_T *qf_find_buf(qf_info_T *qi)
 }
 
 /// Process the 'quickfixtextfunc' option value.
-/// @return  OK or FAIL
-int qf_process_qftf_option(void)
+void qf_process_qftf_option(char **errmsg)
 {
-  return option_set_callback_func(p_qftf, &qftf_cb);
+  if (option_set_callback_func(p_qftf, &qftf_cb) == FAIL) {
+    *errmsg = e_invarg;
+  }
 }
 
 /// Update the w:quickfix_title variable in the quickfix/location list window in
@@ -3859,48 +3883,61 @@ static void qf_update_buffer(qf_info_T *qi, qfline_T *old_last)
 {
   // Check if a buffer for the quickfix list exists.  Update it.
   buf_T *buf = qf_find_buf(qi);
-  if (buf != NULL) {
-    linenr_T old_line_count = buf->b_ml.ml_line_count;
-    int qf_winid = 0;
-
-    win_T *win;
-    if (IS_LL_STACK(qi)) {
-      if (curwin->w_llist == qi) {
-        win = curwin;
-      } else {
-        win = qf_find_win_with_loclist(qi);
-        if (win == NULL) {
-          return;
-        }
+  if (buf == NULL) {
+    return;
+  }
+
+  linenr_T old_line_count = buf->b_ml.ml_line_count;
+  int qf_winid = 0;
+
+  win_T *win;
+  if (IS_LL_STACK(qi)) {
+    if (curwin->w_llist == qi) {
+      win = curwin;
+    } else {
+      // Find the file window (non-quickfix) with this location list
+      win = qf_find_win_with_loclist(qi);
+      if (win == NULL) {
+        // File window is not found. Find the location list window.
+        win = qf_find_win(qi);
+      }
+      if (win == NULL) {
+        return;
       }
-      qf_winid = (int)win->handle;
     }
+    qf_winid = (int)win->handle;
+  }
 
-    aco_save_T aco;
+  // autocommands may cause trouble
+  incr_quickfix_busy();
 
-    if (old_last == NULL) {
-      // set curwin/curbuf to buf and save a few things
-      aucmd_prepbuf(&aco, buf);
-    }
+  aco_save_T aco;
 
-    qf_update_win_titlevar(qi);
+  if (old_last == NULL) {
+    // set curwin/curbuf to buf and save a few things
+    aucmd_prepbuf(&aco, buf);
+  }
 
-    qf_fill_buffer(qf_get_curlist(qi), buf, old_last, qf_winid);
-    buf_inc_changedtick(buf);
+  qf_update_win_titlevar(qi);
 
-    if (old_last == NULL) {
-      (void)qf_win_pos_update(qi, 0);
+  qf_fill_buffer(qf_get_curlist(qi), buf, old_last, qf_winid);
+  buf_inc_changedtick(buf);
 
-      // restore curwin/curbuf and a few other things
-      aucmd_restbuf(&aco);
-    }
+  if (old_last == NULL) {
+    (void)qf_win_pos_update(qi, 0);
 
-    // Only redraw when added lines are visible.  This avoids flickering when
-    // the added lines are not visible.
-    if ((win = qf_find_win(qi)) != NULL && old_line_count < win->w_botline) {
-      redraw_buf_later(buf, NOT_VALID);
-    }
+    // restore curwin/curbuf and a few other things
+    aucmd_restbuf(&aco);
   }
+
+  // Only redraw when added lines are visible.  This avoids flickering when
+  // the added lines are not visible.
+  if ((win = qf_find_win(qi)) != NULL && old_line_count < win->w_botline) {
+    redraw_buf_later(buf, UPD_NOT_VALID);
+  }
+
+  // always called after incr_quickfix_busy()
+  decr_quickfix_busy();
 }
 
 // Add an error line to the quickfix buffer.
@@ -3911,33 +3948,33 @@ static int qf_buf_add_line(qf_list_T *qfl, buf_T *buf, linenr_T lnum, const qfli
   // If the 'quickfixtextfunc' function returned a non-empty custom string
   // for this entry, then use it.
   if (qftf_str != NULL && *qftf_str != NUL) {
-    STRLCPY(IObuff, qftf_str, IOSIZE);
+    xstrlcpy(IObuff, qftf_str, IOSIZE);
   } else {
     buf_T *errbuf;
     int len;
     if (qfp->qf_module != NULL) {
-      STRLCPY(IObuff, qfp->qf_module, IOSIZE);
-      len = (int)STRLEN(IObuff);
+      xstrlcpy(IObuff, qfp->qf_module, IOSIZE);
+      len = (int)strlen(IObuff);
     } else if (qfp->qf_fnum != 0
                && (errbuf = buflist_findnr(qfp->qf_fnum)) != NULL
                && errbuf->b_fname != NULL) {
       if (qfp->qf_type == 1) {  // :helpgrep
-        STRLCPY(IObuff, path_tail(errbuf->b_fname), IOSIZE);
+        xstrlcpy(IObuff, path_tail(errbuf->b_fname), IOSIZE);
       } else {
         // Shorten the file name if not done already.
         // For optimization, do this only for the first entry in a
         // buffer.
         if (first_bufline
             && (errbuf->b_sfname == NULL
-                || path_is_absolute((char_u *)errbuf->b_sfname))) {
+                || path_is_absolute(errbuf->b_sfname))) {
           if (*dirname == NUL) {
-            os_dirname((char_u *)dirname, MAXPATHL);
+            os_dirname(dirname, MAXPATHL);
           }
-          shorten_buf_fname(errbuf, (char_u *)dirname, false);
+          shorten_buf_fname(errbuf, dirname, false);
         }
-        STRLCPY(IObuff, errbuf->b_fname, IOSIZE);
+        xstrlcpy(IObuff, errbuf->b_fname, IOSIZE);
       }
-      len = (int)STRLEN(IObuff);
+      len = (int)strlen(IObuff);
     } else {
       len = 0;
     }
@@ -3945,15 +3982,15 @@ static int qf_buf_add_line(qf_list_T *qfl, buf_T *buf, linenr_T lnum, const qfli
       IObuff[len++] = '|';
     }
     if (qfp->qf_lnum > 0) {
-      qf_range_text(qfp, (char *)IObuff + len, IOSIZE - len);
-      len += (int)STRLEN(IObuff + len);
+      qf_range_text(qfp, IObuff + len, IOSIZE - len);
+      len += (int)strlen(IObuff + len);
 
-      snprintf((char *)IObuff + len, (size_t)(IOSIZE - len), "%s", qf_types(qfp->qf_type,
-                                                                            qfp->qf_nr));
-      len += (int)STRLEN(IObuff + len);
+      snprintf(IObuff + len, (size_t)(IOSIZE - len), "%s", qf_types(qfp->qf_type,
+                                                                    qfp->qf_nr));
+      len += (int)strlen(IObuff + len);
     } else if (qfp->qf_pattern != NULL) {
-      qf_fmt_text(qfp->qf_pattern, (char *)IObuff + len, IOSIZE - len);
-      len += (int)STRLEN(IObuff + len);
+      qf_fmt_text(qfp->qf_pattern, IObuff + len, IOSIZE - len);
+      len += (int)strlen(IObuff + len);
     }
     if (len < IOSIZE - 2) {
       IObuff[len++] = '|';
@@ -3964,11 +4001,11 @@ static int qf_buf_add_line(qf_list_T *qfl, buf_T *buf, linenr_T lnum, const qfli
     // For an unrecognized line keep the indent, the compiler may
     // mark a word with ^^^^.
     qf_fmt_text(len > 3 ? skipwhite(qfp->qf_text) : qfp->qf_text,
-                (char *)IObuff + len, IOSIZE - len);
+                IObuff + len, IOSIZE - len);
   }
 
   if (ml_append_buf(buf, lnum, IObuff,
-                    (colnr_T)STRLEN(IObuff) + 1, false) == FAIL) {
+                    (colnr_T)strlen(IObuff) + 1, false) == FAIL) {
     return FAIL;
   }
   return OK;
@@ -3980,6 +4017,12 @@ static list_T *call_qftf_func(qf_list_T *qfl, int qf_winid, long start_idx, long
 {
   Callback *cb = &qftf_cb;
   list_T *qftf_list = NULL;
+  static bool recursive = false;
+
+  if (recursive) {
+    return NULL;  // this doesn't work properly recursively
+  }
+  recursive = true;
 
   // If 'quickfixtextfunc' is set, then use the user-supplied function to get
   // the text to display. Use the local value of 'quickfixtextfunc' if it is
@@ -4013,6 +4056,7 @@ static list_T *call_qftf_func(qf_list_T *qfl, int qf_winid, long start_idx, long
     tv_dict_unref(dict);
   }
 
+  recursive = false;
   return qftf_list;
 }
 
@@ -4039,7 +4083,7 @@ static void qf_fill_buffer(qf_list_T *qfl, buf_T *buf, qfline_T *old_last, int q
   }
 
   // Check if there is anything to display
-  if (qfl != NULL) {
+  if (qfl != NULL && qfl->qf_start != NULL) {
     char dirname[MAXPATHL];
 
     *dirname = NUL;
@@ -4108,7 +4152,7 @@ static void qf_fill_buffer(qf_list_T *qfl, buf_T *buf, qfline_T *old_last, int q
     // resembles reading a file into a buffer, it's more logical when using
     // autocommands.
     curbuf->b_ro_locked++;
-    set_option_value("ft", 0L, "qf", OPT_LOCAL);
+    set_option_value_give_err("ft", 0L, "qf", OPT_LOCAL);
     curbuf->b_p_ma = false;
 
     keep_filetype = true;                 // don't detect 'filetype'
@@ -4118,7 +4162,7 @@ static void qf_fill_buffer(qf_list_T *qfl, buf_T *buf, qfline_T *old_last, int q
     curbuf->b_ro_locked--;
 
     // make sure it will be redrawn
-    redraw_curbuf_later(NOT_VALID);
+    redraw_curbuf_later(UPD_NOT_VALID);
   }
 
   // Restore KeyTyped, setting 'filetype' may reset it.
@@ -4151,14 +4195,16 @@ static int qf_id2nr(const qf_info_T *const qi, const unsigned qfid)
 static int qf_restore_list(qf_info_T *qi, unsigned save_qfid)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
 {
-  if (qf_get_curlist(qi)->qf_id != save_qfid) {
-    const int curlist = qf_id2nr(qi, save_qfid);
-    if (curlist < 0) {
-      // list is not present
-      return FAIL;
-    }
-    qi->qf_curlist = curlist;
+  if (qf_get_curlist(qi)->qf_id == save_qfid) {
+    return OK;
+  }
+
+  const int curlist = qf_id2nr(qi, save_qfid);
+  if (curlist < 0) {
+    // list is not present
+    return FAIL;
   }
+  qi->qf_curlist = curlist;
   return OK;
 }
 
@@ -4175,15 +4221,14 @@ static void qf_jump_first(qf_info_T *qi, unsigned save_qfid, int forceit)
   }
 }
 
-// Return TRUE when using ":vimgrep" for ":grep".
+// Return true when using ":vimgrep" for ":grep".
 int grep_internal(cmdidx_T cmdidx)
 {
   return (cmdidx == CMD_grep
           || cmdidx == CMD_lgrep
           || cmdidx == CMD_grepadd
           || cmdidx == CMD_lgrepadd)
-         && STRCMP("internal",
-                   *curbuf->b_p_gp == NUL ? p_gp : curbuf->b_p_gp) == 0;
+         && strcmp("internal", *curbuf->b_p_gp == NUL ? p_gp : curbuf->b_p_gp) == 0;
 }
 
 // Return the make/grep autocmd name.
@@ -4213,16 +4258,16 @@ static char *make_get_auname(cmdidx_T cmdidx)
 static char *make_get_fullcmd(const char *makecmd, const char *fname)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_NONNULL_RET
 {
-  size_t len = STRLEN(p_shq) * 2 + STRLEN(makecmd) + 1;
+  size_t len = strlen(p_shq) * 2 + strlen(makecmd) + 1;
   if (*p_sp != NUL) {
-    len += STRLEN(p_sp) + STRLEN(fname) + 3;
+    len += strlen(p_sp) + strlen(fname) + 3;
   }
   char *const cmd = xmalloc(len);
-  snprintf(cmd, len, "%s%s%s", (char *)p_shq, (char *)makecmd, (char *)p_shq);
+  snprintf(cmd, len, "%s%s%s", p_shq, (char *)makecmd, p_shq);
 
   // If 'shellpipe' empty: don't redirect to 'errorfile'.
   if (*p_sp != NUL) {
-    append_redir(cmd, len, (char *)p_sp, (char *)fname);
+    append_redir(cmd, len, p_sp, (char *)fname);
   }
 
   // Display the fully formed command.  Output a newline if there's something
@@ -4241,7 +4286,7 @@ static char *make_get_fullcmd(const char *makecmd, const char *fname)
 // Used for ":make", ":lmake", ":grep", ":lgrep", ":grepadd", and ":lgrepadd"
 void ex_make(exarg_T *eap)
 {
-  char *enc = (*curbuf->b_p_menc != NUL) ? (char *)curbuf->b_p_menc : (char *)p_menc;
+  char *enc = (*curbuf->b_p_menc != NUL) ? curbuf->b_p_menc : p_menc;
 
   // Redirect ":grep" to ":vimgrep" if 'grepprg' is "internal".
   if (grep_internal(eap->cmdidx)) {
@@ -4275,10 +4320,17 @@ void ex_make(exarg_T *eap)
 
   incr_quickfix_busy();
 
-  int res = qf_init(wp, fname, (eap->cmdidx != CMD_make
-                                && eap->cmdidx != CMD_lmake) ? p_gefm : p_efm,
-                    (eap->cmdidx != CMD_grepadd && eap->cmdidx != CMD_lgrepadd),
-                    qf_cmdtitle(*eap->cmdlinep), enc);
+  char *errorformat = p_efm;
+  bool newlist = true;
+
+  if (eap->cmdidx != CMD_make && eap->cmdidx != CMD_lmake) {
+    errorformat = p_gefm;
+  }
+  if (eap->cmdidx == CMD_grepadd || eap->cmdidx == CMD_lgrepadd) {
+    newlist = false;
+  }
+
+  int res = qf_init(wp, fname, errorformat, newlist, qf_cmdtitle(*eap->cmdlinep), enc);
 
   qf_info_T *qi = &ql_info;
   if (wp != NULL) {
@@ -4319,7 +4371,7 @@ static char *get_mef_name(void)
   static int off = 0;
 
   if (*p_mef == NUL) {
-    name = (char *)vim_tempname();
+    name = vim_tempname();
     if (name == NULL) {
       emsg(_(e_notmp));
     }
@@ -4328,7 +4380,7 @@ static char *get_mef_name(void)
 
   char *p;
 
-  for (p = p_mef; *p; ++p) {
+  for (p = p_mef; *p; p++) {
     if (p[0] == '#' && p[1] == '#') {
       break;
     }
@@ -4345,9 +4397,9 @@ static char *get_mef_name(void)
     } else {
       off += 19;
     }
-    name = xmalloc(STRLEN(p_mef) + 30);
+    name = xmalloc(strlen(p_mef) + 30);
     STRCPY(name, p_mef);
-    snprintf(name + (p - p_mef), STRLEN(name), "%d%d", start, off);
+    snprintf(name + (p - p_mef), strlen(name), "%d%d", start, off);
     STRCAT(name, p + 2);
     // Don't accept a symbolic link, it's a security risk.
     FileInfo file_info;
@@ -4832,7 +4884,7 @@ static void qf_get_nth_below_entry(qfline_T *entry_arg, linenr_T n, bool linewis
 }
 
 /// Get the nth quickfix entry above the specified entry.  Searches backwards in
-/// the list. If linewise is TRUE, then treat multiple entries on a single line
+/// the list. If linewise is true, then treat multiple entries on a single line
 /// as one.
 static void qf_get_nth_above_entry(qfline_T *entry, linenr_T n, bool linewise, int *errornr)
   FUNC_ATTR_NONNULL_ALL
@@ -4898,7 +4950,7 @@ void ex_cbelow(exarg_T *eap)
                       || eap->cmdidx == CMD_cafter) ? BUF_HAS_QF_ENTRY : BUF_HAS_LL_ENTRY;
 
   if (!(curbuf->b_has_qf_entry & buf_has_flag)) {
-    emsg(_(e_quickfix));
+    emsg(_(e_no_errors));
     return;
   }
 
@@ -4910,7 +4962,7 @@ void ex_cbelow(exarg_T *eap)
   qf_list_T *qfl = qf_get_curlist(qi);
   // check if the list has valid errors
   if (!qf_list_has_valid_entries(qfl)) {
-    emsg(_(e_quickfix));
+    emsg(_(e_no_errors));
     return;
   }
 
@@ -4981,7 +5033,7 @@ void ex_cfile(exarg_T *eap)
     set_string_option_direct("ef", -1, eap->arg, OPT_FREE, 0);
   }
 
-  char *enc = (*curbuf->b_p_menc != NUL) ? (char *)curbuf->b_p_menc : (char *)p_menc;
+  char *enc = (*curbuf->b_p_menc != NUL) ? curbuf->b_p_menc : p_menc;
 
   if (is_loclist_cmd(eap->cmdidx)) {
     wp = curwin;
@@ -4997,8 +5049,8 @@ void ex_cfile(exarg_T *eap)
   // first error.
   // :caddfile adds to an existing quickfix list. If there is no
   // quickfix list then a new list is created.
-  int res = qf_init(wp, (char *)p_ef, p_efm, (eap->cmdidx != CMD_caddfile
-                                              && eap->cmdidx != CMD_laddfile),
+  int res = qf_init(wp, p_ef, p_efm, (eap->cmdidx != CMD_caddfile
+                                      && eap->cmdidx != CMD_laddfile),
                     qf_cmdtitle(*eap->cmdlinep), enc);
   if (wp != NULL) {
     qi = GET_LOC_LIST(wp);
@@ -5062,7 +5114,7 @@ static void vgr_init_regmatch(regmmatch_T *regmatch, char *s)
       emsg(_(e_noprevre));
       return;
     }
-    regmatch->regprog = vim_regcomp((char *)last_search_pat(), RE_MAGIC);
+    regmatch->regprog = vim_regcomp(last_search_pat(), RE_MAGIC);
   } else {
     regmatch->regprog = vim_regcomp(s, RE_MAGIC);
   }
@@ -5075,7 +5127,7 @@ static void vgr_init_regmatch(regmmatch_T *regmatch, char *s)
 static void vgr_display_fname(char *fname)
 {
   msg_start();
-  char *p = (char *)msg_strtrunc((char_u *)fname, true);
+  char *p = msg_strtrunc(fname, true);
   if (p == NULL) {
     msg_outtrans(fname);
   } else {
@@ -5120,11 +5172,10 @@ static bool vgr_qflist_valid(win_T *wp, qf_info_T *qi, unsigned qfid, char *titl
       // An autocmd has freed the location list
       emsg(_(e_current_location_list_was_changed));
       return false;
-    } else {
-      // Quickfix list is not found, create a new one.
-      qf_new_list(qi, title);
-      return true;
     }
+    // Quickfix list is not found, create a new one.
+    qf_new_list(qi, title);
+    return true;
   }
   if (qf_restore_list(qi, qfid) == FAIL) {
     return false;
@@ -5140,6 +5191,7 @@ static bool vgr_match_buflines(qf_list_T *qfl, char *fname, buf_T *buf, char *sp
   FUNC_ATTR_NONNULL_ARG(1, 3, 4, 5, 6)
 {
   bool found_match = false;
+  const size_t pat_len = strlen(spat);
 
   for (linenr_T lnum = 1; lnum <= buf->b_ml.ml_line_count && *tomatch > 0; lnum++) {
     colnr_T col = 0;
@@ -5154,7 +5206,7 @@ static bool vgr_match_buflines(qf_list_T *qfl, char *fname, buf_T *buf, char *sp
                          fname,
                          NULL,
                          duplicate_name ? 0 : buf->b_fnum,
-                         (char *)ml_get_buf(buf, regmatch->startpos[0].lnum + lnum, false),
+                         ml_get_buf(buf, regmatch->startpos[0].lnum + lnum, false),
                          regmatch->startpos[0].lnum + lnum,
                          regmatch->endpos[0].lnum + lnum,
                          regmatch->startpos[0].col + 1,
@@ -5176,20 +5228,18 @@ static bool vgr_match_buflines(qf_list_T *qfl, char *fname, buf_T *buf, char *sp
           break;
         }
         col = regmatch->endpos[0].col + (col == regmatch->endpos[0].col);
-        if (col > (colnr_T)STRLEN(ml_get_buf(buf, lnum, false))) {
+        if (col > (colnr_T)strlen(ml_get_buf(buf, lnum, false))) {
           break;
         }
       }
     } else {
-      const size_t pat_len = STRLEN(spat);
-      char *const str = (char *)ml_get_buf(buf, lnum, false);
+      char *const str = ml_get_buf(buf, lnum, false);
       int score;
       uint32_t matches[MAX_FUZZY_MATCHES];
       const size_t sz = sizeof(matches) / sizeof(matches[0]);
 
       // Fuzzy string match
-      while (fuzzy_match((char_u *)str + col, (char_u *)spat, false, &score, matches,
-                         (int)sz) > 0) {
+      while (fuzzy_match(str + col, spat, false, &score, matches, (int)sz) > 0) {
         // Pass the buffer number so that it gets used even for a
         // dummy buffer, unless duplicate_name is set, then the
         // buffer will be wiped out below.
@@ -5220,7 +5270,7 @@ static bool vgr_match_buflines(qf_list_T *qfl, char *fname, buf_T *buf, char *sp
           break;
         }
         col = (colnr_T)matches[pat_len - 1] + col + 1;
-        if (col > (colnr_T)STRLEN(str)) {
+        if (col > (colnr_T)strlen(str)) {
           break;
         }
       }
@@ -5236,7 +5286,7 @@ static bool vgr_match_buflines(qf_list_T *qfl, char *fname, buf_T *buf, char *sp
 
 /// Jump to the first match and update the directory.
 static void vgr_jump_to_match(qf_info_T *qi, int forceit, bool *redraw_for_dummy,
-                              buf_T *first_match_buf, char *target_dir)
+                              buf_T *first_match_buf, char *target_dir)  // NOLINT(readability-non-const-parameter)
 {
   buf_T *buf = curbuf;
   qf_jump(qi, 0, 0, forceit);
@@ -5262,8 +5312,8 @@ static bool existing_swapfile(const buf_T *buf)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 {
   if (buf->b_ml.ml_mfp != NULL && buf->b_ml.ml_mfp->mf_fname != NULL) {
-    const char *const fname = (char *)buf->b_ml.ml_mfp->mf_fname;
-    const size_t len = STRLEN(fname);
+    const char *const fname = buf->b_ml.ml_mfp->mf_fname;
+    const size_t len = strlen(fname);
 
     return fname[len - 1] != 'p' || fname[len - 2] != 'w';
   }
@@ -5305,10 +5355,8 @@ static int vgr_process_args(exarg_T *eap, vgr_args_T *args)
   }
 
   // Parse the list of arguments, wildcards have already been expanded.
-  if (get_arglist_exp((char_u *)p, &args->fcount, &args->fnames, true) == FAIL) {
-    return FAIL;
-  }
-  if (args->fcount == 0) {
+  if (get_arglist_exp(p, &args->fcount, &args->fnames, true) == FAIL
+      || args->fcount == 0) {
     emsg(_(e_nomatch));
     return FAIL;
   }
@@ -5330,11 +5378,11 @@ static int vgr_process_files(win_T *wp, qf_info_T *qi, vgr_args_T *cmd_args, boo
 
   // Remember the current directory, because a BufRead autocommand that does
   // ":lcd %:p:h" changes the meaning of short path names.
-  os_dirname((char_u *)dirname_start, MAXPATHL);
+  os_dirname(dirname_start, MAXPATHL);
 
   time_t seconds = (time_t)0;
   for (int fi = 0; fi < cmd_args->fcount && !got_int && cmd_args->tomatch > 0; fi++) {
-    char *fname = (char *)path_try_shorten_fname((char_u *)cmd_args->fnames[fi]);
+    char *fname = path_try_shorten_fname(cmd_args->fnames[fi]);
     if (time(NULL) > seconds) {
       // Display the file name every second or so, show the user we are
       // working on it.
@@ -5419,7 +5467,7 @@ static int vgr_process_files(win_T *wp, qf_info_T *qi, vgr_args_T *cmd_args, boo
           // directory we jumped to below.
           if (buf == *first_match_buf
               && *target_dir == NULL
-              && STRCMP(dirname_start, dirname_now) != 0) {
+              && strcmp(dirname_start, dirname_now) != 0) {
             *target_dir = xstrdup(dirname_now);
           }
 
@@ -5429,7 +5477,7 @@ static int vgr_process_files(win_T *wp, qf_info_T *qi, vgr_args_T *cmd_args, boo
           // options!
           aco_save_T aco;
           aucmd_prepbuf(&aco, buf);
-          apply_autocmds(EVENT_FILETYPE, (char *)buf->b_p_ft, buf->b_fname, true, buf);
+          apply_autocmds(EVENT_FILETYPE, buf->b_p_ft, buf->b_fname, true, buf);
           do_modelines(OPT_NOWIN);
           aucmd_restbuf(&aco);
         }
@@ -5541,8 +5589,8 @@ static void restore_start_dir(char *dirname_start)
 {
   char *dirname_now = xmalloc(MAXPATHL);
 
-  os_dirname((char_u *)dirname_now, MAXPATHL);
-  if (STRCMP(dirname_start, dirname_now) != 0) {
+  os_dirname(dirname_now, MAXPATHL);
+  if (strcmp(dirname_start, dirname_now) != 0) {
     // If the directory has changed, change it back by building up an
     // appropriate ex command and executing it.
     exarg_T ea = {
@@ -5609,7 +5657,7 @@ static buf_T *load_dummy_buffer(char *fname, char *dirname_start, char *resultin
     if (readfile_result == OK
         && !got_int
         && !(curbuf->b_flags & BF_NEW)) {
-      failed = FALSE;
+      failed = false;
       if (curbuf != newbuf) {
         // Bloody autocommands changed the buffer!  Can happen when
         // using netrw and editing a remote file.  Use the current
@@ -5622,6 +5670,7 @@ static buf_T *load_dummy_buffer(char *fname, char *dirname_start, char *resultin
 
     // Restore curwin/curbuf and a few other things.
     aucmd_restbuf(&aco);
+
     if (newbuf_to_wipe.br_buf != NULL && bufref_valid(&newbuf_to_wipe)) {
       wipe_buffer(newbuf_to_wipe.br_buf, false);
     }
@@ -5634,7 +5683,7 @@ static buf_T *load_dummy_buffer(char *fname, char *dirname_start, char *resultin
   // When autocommands/'autochdir' option changed directory: go back.
   // Let the caller know what the resulting dir was first, in case it is
   // important.
-  os_dirname((char_u *)resulting_dir, MAXPATHL);
+  os_dirname(resulting_dir, MAXPATHL);
   restore_start_dir(dirname_start);
 
   if (!bufref_valid(&newbufref)) {
@@ -5677,7 +5726,7 @@ static void wipe_dummy_buffer(buf_T *buf, char *dirname_start)
     cleanup_T cs;
 
     // Reset the error/interrupt/exception state here so that aborting()
-    // returns FALSE when wiping out the buffer.  Otherwise it doesn't
+    // returns false when wiping out the buffer.  Otherwise it doesn't
     // work when got_int is set.
     enter_cleanup(&cs);
 
@@ -5696,12 +5745,14 @@ static void wipe_dummy_buffer(buf_T *buf, char *dirname_start)
 // 'autochdir' option have changed it.
 static void unload_dummy_buffer(buf_T *buf, char *dirname_start)
 {
-  if (curbuf != buf) {          // safety check
-    close_buffer(NULL, buf, DOBUF_UNLOAD, false, true);
-
-    // When autocommands/'autochdir' option changed directory: go back.
-    restore_start_dir(dirname_start);
+  if (curbuf == buf) {          // safety check
+    return;
   }
+
+  close_buffer(NULL, buf, DOBUF_UNLOAD, false, true);
+
+  // When autocommands/'autochdir' option changed directory: go back.
+  restore_start_dir(dirname_start);
 }
 
 /// Copy the specified quickfix entry items into a new dict and append the dict
@@ -5826,32 +5877,34 @@ static int qf_get_list_from_lines(dict_T *what, dictitem_T *di, dict_T *retdict)
   int status = FAIL;
 
   // Only a List value is supported
-  if (di->di_tv.v_type == VAR_LIST && di->di_tv.vval.v_list != NULL) {
-    char *errorformat = p_efm;
-    dictitem_T *efm_di;
-    // If errorformat is supplied then use it, otherwise use the 'efm'
-    // option setting
-    if ((efm_di = tv_dict_find(what, S_LEN("efm"))) != NULL) {
-      if (efm_di->di_tv.v_type != VAR_STRING
-          || efm_di->di_tv.vval.v_string == NULL) {
-        return FAIL;
-      }
-      errorformat = efm_di->di_tv.vval.v_string;
-    }
-
-    list_T *l = tv_list_alloc(kListLenMayKnow);
-    qf_info_T *const qi = qf_alloc_stack(QFLT_INTERNAL);
+  if (di->di_tv.v_type != VAR_LIST || di->di_tv.vval.v_list == NULL) {
+    return FAIL;
+  }
 
-    if (qf_init_ext(qi, 0, NULL, NULL, &di->di_tv, errorformat,
-                    true, (linenr_T)0, (linenr_T)0, NULL, NULL) > 0) {
-      (void)get_errorlist(qi, NULL, 0, 0, l);
-      qf_free(&qi->qf_lists[0]);
+  char *errorformat = p_efm;
+  dictitem_T *efm_di;
+  // If errorformat is supplied then use it, otherwise use the 'efm'
+  // option setting
+  if ((efm_di = tv_dict_find(what, S_LEN("efm"))) != NULL) {
+    if (efm_di->di_tv.v_type != VAR_STRING
+        || efm_di->di_tv.vval.v_string == NULL) {
+      return FAIL;
     }
-    xfree(qi);
+    errorformat = efm_di->di_tv.vval.v_string;
+  }
+
+  list_T *l = tv_list_alloc(kListLenMayKnow);
+  qf_info_T *const qi = qf_alloc_stack(QFLT_INTERNAL);
 
-    tv_dict_add_list(retdict, S_LEN("items"), l);
-    status = OK;
+  if (qf_init_ext(qi, 0, NULL, NULL, &di->di_tv, errorformat,
+                  true, (linenr_T)0, (linenr_T)0, NULL, NULL) > 0) {
+    (void)get_errorlist(qi, NULL, 0, 0, l);
+    qf_free(&qi->qf_lists[0]);
   }
+  xfree(qi);
+
+  tv_dict_add_list(retdict, S_LEN("items"), l);
+  status = OK;
 
   return status;
 }
@@ -6500,7 +6553,7 @@ static int qf_setprop_curidx(qf_info_T *qi, qf_list_T *qfl, const dictitem_T *di
   // If the specified index is '$', then use the last entry
   if (di->di_tv.v_type == VAR_STRING
       && di->di_tv.vval.v_string != NULL
-      && STRCMP(di->di_tv.vval.v_string, "$") == 0) {
+      && strcmp(di->di_tv.vval.v_string, "$") == 0) {
     newidx = qfl->qf_count;
   } else {
     // Otherwise use the specified index
@@ -6668,7 +6721,8 @@ int set_errorlist(win_T *wp, list_T *list, int action, char *title, dict_T *what
   return retval;
 }
 
-/// Mark the context as in use for all the lists in a quickfix stack.
+/// Mark the quickfix context and callback function as in use for all the lists
+/// in a quickfix stack.
 static bool mark_quickfix_ctx(qf_info_T *qi, int copyID)
 {
   bool abort = false;
@@ -6679,6 +6733,9 @@ static bool mark_quickfix_ctx(qf_info_T *qi, int copyID)
         && ctx->v_type != VAR_STRING && ctx->v_type != VAR_FLOAT) {
       abort = set_ref_in_item(ctx, copyID, NULL, NULL);
     }
+
+    Callback *cb = &qi->qf_lists[i].qf_qftf_cb;
+    abort = abort || set_ref_in_callback(cb, copyID, NULL, NULL);
   }
 
   return abort;
@@ -6693,6 +6750,11 @@ bool set_ref_in_quickfix(int copyID)
     return abort;
   }
 
+  abort = set_ref_in_callback(&qftf_cb, copyID, NULL, NULL);
+  if (abort) {
+    return abort;
+  }
+
   FOR_ALL_TAB_WINDOWS(tp, win) {
     if (win->w_llist != NULL) {
       abort = mark_quickfix_ctx(win->w_llist, copyID);
@@ -6806,8 +6868,8 @@ void ex_cbuffer(exarg_T *eap)
   char *qf_title = qf_cmdtitle(*eap->cmdlinep);
 
   if (buf->b_sfname) {
-    vim_snprintf((char *)IObuff, IOSIZE, "%s (%s)", qf_title, buf->b_sfname);
-    qf_title = (char *)IObuff;
+    vim_snprintf(IObuff, IOSIZE, "%s (%s)", qf_title, buf->b_sfname);
+    qf_title = IObuff;
   }
 
   incr_quickfix_busy();
@@ -6885,43 +6947,45 @@ void ex_cexpr(exarg_T *eap)
   // Evaluate the expression.  When the result is a string or a list we can
   // use it to fill the errorlist.
   typval_T tv;
-  if (eval0(eap->arg, &tv, &eap->nextcmd, true) != FAIL) {
-    if ((tv.v_type == VAR_STRING && tv.vval.v_string != NULL)
-        || tv.v_type == VAR_LIST) {
-      incr_quickfix_busy();
-      int res = qf_init_ext(qi, qi->qf_curlist, NULL, NULL, &tv, p_efm,
-                            (eap->cmdidx != CMD_caddexpr
-                             && eap->cmdidx != CMD_laddexpr),
-                            (linenr_T)0, (linenr_T)0,
-                            qf_cmdtitle(*eap->cmdlinep), NULL);
-      if (qf_stack_empty(qi)) {
-        decr_quickfix_busy();
-        goto cleanup;
-      }
-      if (res >= 0) {
-        qf_list_changed(qf_get_curlist(qi));
-      }
-      // Remember the current quickfix list identifier, so that we can
-      // check for autocommands changing the current quickfix list.
-      unsigned save_qfid = qf_get_curlist(qi)->qf_id;
-      if (au_name != NULL) {
-        apply_autocmds(EVENT_QUICKFIXCMDPOST, au_name, curbuf->b_fname, true, curbuf);
-      }
-      // Jump to the first error for a new list and if autocmds didn't
-      // free the list.
-      if (res > 0
-          && (eap->cmdidx == CMD_cexpr || eap->cmdidx == CMD_lexpr)
-          && qflist_valid(wp, save_qfid)) {
-        // display the first error
-        qf_jump_first(qi, save_qfid, eap->forceit);
-      }
+  if (eval0(eap->arg, &tv, &eap->nextcmd, true) == FAIL) {
+    return;
+  }
+
+  if ((tv.v_type == VAR_STRING && tv.vval.v_string != NULL)
+      || tv.v_type == VAR_LIST) {
+    incr_quickfix_busy();
+    int res = qf_init_ext(qi, qi->qf_curlist, NULL, NULL, &tv, p_efm,
+                          (eap->cmdidx != CMD_caddexpr
+                           && eap->cmdidx != CMD_laddexpr),
+                          (linenr_T)0, (linenr_T)0,
+                          qf_cmdtitle(*eap->cmdlinep), NULL);
+    if (qf_stack_empty(qi)) {
       decr_quickfix_busy();
-    } else {
-      emsg(_("E777: String or List expected"));
+      goto cleanup;
     }
-cleanup:
-    tv_clear(&tv);
+    if (res >= 0) {
+      qf_list_changed(qf_get_curlist(qi));
+    }
+    // Remember the current quickfix list identifier, so that we can
+    // check for autocommands changing the current quickfix list.
+    unsigned save_qfid = qf_get_curlist(qi)->qf_id;
+    if (au_name != NULL) {
+      apply_autocmds(EVENT_QUICKFIXCMDPOST, au_name, curbuf->b_fname, true, curbuf);
+    }
+    // Jump to the first error for a new list and if autocmds didn't
+    // free the list.
+    if (res > 0
+        && (eap->cmdidx == CMD_cexpr || eap->cmdidx == CMD_lexpr)
+        && qflist_valid(wp, save_qfid)) {
+      // display the first error
+      qf_jump_first(qi, save_qfid, eap->forceit);
+    }
+    decr_quickfix_busy();
+  } else {
+    emsg(_("E777: String or List expected"));
   }
+cleanup:
+  tv_clear(&tv);
 }
 
 // Get the location list for ":lhelpgrep"
@@ -6952,10 +7016,10 @@ static void hgr_search_file(qf_list_T *qfl, char *fname, regmatch_T *p_regmatch)
 
   linenr_T lnum = 1;
   while (!vim_fgets(IObuff, IOSIZE, fd) && !got_int) {
-    char *line = (char *)IObuff;
+    char *line = IObuff;
 
     if (vim_regexec(p_regmatch, line, (colnr_T)0)) {
-      int l = (int)STRLEN(line);
+      int l = (int)strlen(line);
 
       // remove trailing CR, LF, spaces, etc.
       while (l > 0 && line[l - 1] <= ' ') {
@@ -6970,8 +7034,8 @@ static void hgr_search_file(qf_list_T *qfl, char *fname, regmatch_T *p_regmatch)
                        line,
                        lnum,
                        0,
-                       (int)(p_regmatch->startp[0] - (char_u *)line) + 1,  // col
-                       (int)(p_regmatch->endp[0] - (char_u *)line)
+                       (int)(p_regmatch->startp[0] - line) + 1,  // col
+                       (int)(p_regmatch->endp[0] - line)
                        + 1,    // end_col
                        false,  // vis_col
                        NULL,   // search pattern
@@ -6980,13 +7044,13 @@ static void hgr_search_file(qf_list_T *qfl, char *fname, regmatch_T *p_regmatch)
                        true)    // valid
           == QF_FAIL) {
         got_int = true;
-        if ((char_u *)line != IObuff) {
+        if (line != IObuff) {
           xfree(line);
         }
         break;
       }
     }
-    if ((char_u *)line != IObuff) {
+    if (line != IObuff) {
       xfree(line);
     }
     lnum++;
@@ -7012,9 +7076,9 @@ static void hgr_search_files_in_dir(qf_list_T *qfl, char *dirname, regmatch_T *p
     for (int fi = 0; fi < fcount && !got_int; fi++) {
       // Skip files for a different language.
       if (lang != NULL
-          && STRNICMP(lang, fnames[fi] + STRLEN(fnames[fi]) - 3, 2) != 0
+          && STRNICMP(lang, fnames[fi] + strlen(fnames[fi]) - 3, 2) != 0
           && !(STRNICMP(lang, "en", 2) == 0
-               && STRNICMP("txt", fnames[fi] + STRLEN(fnames[fi]) - 3, 3)
+               && STRNICMP("txt", fnames[fi] + strlen(fnames[fi]) - 3, 3)
                == 0)) {
         continue;
       }
@@ -7033,11 +7097,11 @@ static void hgr_search_in_rtp(qf_list_T *qfl, regmatch_T *p_regmatch, const char
   FUNC_ATTR_NONNULL_ARG(1, 2)
 {
   // Go through all directories in 'runtimepath'
-  char *p = (char *)p_rtp;
+  char *p = p_rtp;
   while (*p != NUL && !got_int) {
-    copy_option_part(&p, (char *)NameBuff, MAXPATHL, ",");
+    copy_option_part(&p, NameBuff, MAXPATHL, ",");
 
-    hgr_search_files_in_dir(qfl, (char *)NameBuff, p_regmatch, (char *)lang);
+    hgr_search_files_in_dir(qfl, NameBuff, p_regmatch, (char *)lang);
   }
 }
 
@@ -7045,7 +7109,7 @@ static void hgr_search_in_rtp(qf_list_T *qfl, regmatch_T *p_regmatch, const char
 void ex_helpgrep(exarg_T *eap)
 {
   qf_info_T *qi = &ql_info;
-  char *au_name =  NULL;
+  char *au_name = NULL;
 
   switch (eap->cmdidx) {
   case CMD_helpgrep:
@@ -7062,9 +7126,11 @@ void ex_helpgrep(exarg_T *eap)
     }
   }
 
+  bool updated = false;
   // Make 'cpoptions' empty, the 'l' flag should not be used here.
   char *const save_cpo = p_cpo;
-  p_cpo = (char *)empty_option;
+  const bool save_cpo_allocated = is_option_allocated("cpo");
+  p_cpo = empty_option;
 
   bool new_qi = false;
   if (is_loclist_cmd(eap->cmdidx)) {
@@ -7092,14 +7158,26 @@ void ex_helpgrep(exarg_T *eap)
     qfl->qf_ptr = qfl->qf_start;
     qfl->qf_index = 1;
     qf_list_changed(qfl);
-    qf_update_buffer(qi, NULL);
+    updated = true;
   }
 
-  if ((char_u *)p_cpo == empty_option) {
+  if (p_cpo == empty_option) {
     p_cpo = save_cpo;
   } else {
-    // Darn, some plugin changed the value.
-    free_string_option((char_u *)save_cpo);
+    // Darn, some plugin changed the value.  If it's still empty it was
+    // changed and restored, need to restore in the complicated way.
+    if (*p_cpo == NUL) {
+      set_option_value_give_err("cpo", 0L, save_cpo, 0);
+    }
+    if (save_cpo_allocated) {
+      free_string_option(save_cpo);
+    }
+  }
+
+  if (updated) {
+    // This may open a window and source scripts, do this after 'cpo' was
+    // restored.
+    qf_update_buffer(qi, NULL);
   }
 
   if (au_name != NULL) {
@@ -7128,7 +7206,9 @@ void ex_helpgrep(exarg_T *eap)
       if (new_qi) {
         ll_free_all(&qi);
       }
-    } else if (curwin->w_llist == NULL) {
+    } else if (curwin->w_llist == NULL && new_qi) {
+      // current window didn't have a location list associated with it
+      // before. Associate the new location list now.
       curwin->w_llist = qi;
     }
   }
@@ -7158,14 +7238,14 @@ static void get_qf_loc_list(int is_qf, win_T *wp, typval_T *what_arg, typval_T *
 }
 
 /// "getloclist()" function
-void f_getloclist(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_getloclist(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   win_T *wp = find_win_by_nr_or_id(&argvars[0]);
   get_qf_loc_list(false, wp, &argvars[1], rettv);
 }
 
 /// "getqflist()" functions
-void f_getqflist(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_getqflist(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   get_qf_loc_list(true, NULL, &argvars[0], rettv);
 }
@@ -7252,7 +7332,7 @@ skip_args:
 }
 
 /// "setloclist()" function
-void f_setloclist(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_setloclist(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   rettv->vval.v_number = -1;
 
@@ -7263,7 +7343,7 @@ void f_setloclist(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 }
 
 /// "setqflist()" function
-void f_setqflist(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+void f_setqflist(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   set_qf_ll_list(NULL, argvars, rettv);
 }