Merge #9842 from mhinz/vim-8.0.1782

vim-patch:8.0.{1353,1389,1406,1420,1432,1500,1569,1634,1678,1727,1782,1805,1831}

3 files changed, 1387 insertions, 545 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index d5131e976a..06054b53ec 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -14892,7 +14892,7 @@ static void set_qf_ll_list(win_T *wp, typval_T *args, typval_T *rettv)
 
 skip_args:
   if (!title) {
-    title = (wp ? "setloclist()" : "setqflist()");
+    title = (wp ? ":setloclist()" : ":setqflist()");
   }
 
   recursive++;
diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index 2ee5af1ea5..8696754baf 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -57,19 +57,20 @@ struct dir_stack_T {
  */
 typedef struct qfline_S qfline_T;
 struct qfline_S {
-  qfline_T    *qf_next;         /* pointer to next error in the list */
-  qfline_T    *qf_prev;         /* pointer to previous error in the list */
-  linenr_T qf_lnum;             /* line number where the error occurred */
-  int qf_fnum;                  /* file number for the line */
-  int qf_col;                   /* column where the error occurred */
-  int qf_nr;                    /* error number */
-  char_u      *qf_pattern;      /* search pattern for the error */
-  char_u      *qf_text;         /* description of the error */
-  char_u qf_viscol;             /* set to TRUE if qf_col is screen column */
-  char_u qf_cleared;            /* set to TRUE if line has been deleted */
-  char_u qf_type;               /* type of the error (mostly 'E'); 1 for
-                                   :helpgrep */
-  char_u qf_valid;              /* valid error message detected */
+  qfline_T    *qf_next;         ///< pointer to next error in the list
+  qfline_T    *qf_prev;         ///< pointer to previous error in the list
+  linenr_T qf_lnum;             ///< line number where the error occurred
+  int qf_fnum;                  ///< file number for the line
+  int qf_col;                   ///< column where the error occurred
+  int qf_nr;                    ///< error number
+  char_u      *qf_module;       ///< module name for this error
+  char_u      *qf_pattern;      ///< search pattern for the error
+  char_u      *qf_text;         ///< description of the error
+  char_u qf_viscol;             ///< set to TRUE if qf_col is screen column
+  char_u qf_cleared;            ///< set to TRUE if line has been deleted
+  char_u qf_type;               ///< type of the error (mostly 'E'); 1 for
+                                //   :helpgrep
+  char_u qf_valid;              ///< valid error message detected
 };
 
 /*
@@ -101,6 +102,7 @@ typedef struct qf_list_S {
   bool qf_multiline;
   bool qf_multiignore;
   bool qf_multiscan;
+  long qf_changedtick;
 } qf_list_T;
 
 /// Quickfix/Location list stack definition
@@ -121,7 +123,7 @@ struct qf_info_S {
 static qf_info_T ql_info;         // global quickfix list
 static unsigned last_qf_id = 0;   // Last Used quickfix list id
 
-#define FMT_PATTERNS 10         /* maximum number of % recognized */
+#define FMT_PATTERNS 11           // maximum number of % recognized
 
 /*
  * Structure used to hold the info of one part of 'errorformat'
@@ -155,7 +157,8 @@ enum {
   QF_OK = 1,
   QF_END_OF_INPUT = 2,
   QF_NOMEM = 3,
-  QF_IGNORE_LINE = 4
+  QF_IGNORE_LINE = 4,
+  QF_MULTISCAN = 5,
 };
 
 typedef struct {
@@ -176,6 +179,7 @@ typedef struct {
 
 typedef struct {
   char_u *namebuf;
+  char_u *module;
   char_u *errmsg;
   size_t errmsglen;
   long lnum;
@@ -205,6 +209,8 @@ typedef struct {
 static char_u *qf_last_bufname = NULL;
 static bufref_T  qf_last_bufref = { NULL, 0, 0 };
 
+static char *e_loc_list_changed = N_("E926: Current location list was changed");
+
 /// Read the errorfile "efile" into memory, line by line, building the error
 /// list. Set the error list's title to qf_title.
 ///
@@ -247,7 +253,8 @@ static struct fmtpattern
   { 'r', ".*" },
   { 'p', "[- 	.]*" },  // NOLINT(whitespace/tab)
   { 'v', "\\d\\+" },
-  { 's', ".\\+" }
+  { 's', ".\\+" },
+  { 'o', ".\\+" }
 };
 
 // Converts a 'errorformat' string to regular expression pattern
@@ -717,20 +724,17 @@ static int qf_parse_line(qf_info_T *qi, int qf_idx, char_u *linebuf,
                          size_t linelen, efm_T *fmt_first, qffields_T *fields)
 {
   efm_T *fmt_ptr;
-  size_t len;
-  int    i;
   int    idx = 0;
   char_u *tail = NULL;
-  regmatch_T regmatch;
   qf_list_T *qfl = &qi->qf_lists[qf_idx];
+  int status;
 
-  // Always ignore case when looking for a matching error.
-  regmatch.rm_ic = true;
-
+restofline:
   // If there was no %> item start at the first pattern
   if (fmt_start == NULL) {
     fmt_ptr = fmt_first;
   } else {
+    // Otherwise start from the last used pattern.
     fmt_ptr = fmt_start;
     fmt_start = NULL;
   }
@@ -738,143 +742,15 @@ static int qf_parse_line(qf_info_T *qi, int qf_idx, char_u *linebuf,
   // Try to match each part of 'errorformat' until we find a complete
   // match or no match.
   fields->valid = true;
-restofline:
   for (; fmt_ptr != NULL; fmt_ptr = fmt_ptr->next) {
     idx = fmt_ptr->prefix;
-    if (qfl->qf_multiscan && vim_strchr((char_u *)"OPQ", idx) == NULL) {
-      continue;
+    status = qf_parse_get_fields(linebuf, linelen, fmt_ptr, fields,
+                                 qfl->qf_multiline, qfl->qf_multiscan,
+                                 &tail);
+    if (status == QF_NOMEM) {
+      return status;
     }
-    fields->namebuf[0] = NUL;
-    fields->pattern[0] = NUL;
-    if (!qfl->qf_multiscan) {
-      fields->errmsg[0] = NUL;
-    }
-    fields->lnum = 0;
-    fields->col = 0;
-    fields->use_viscol = false;
-    fields->enr = -1;
-    fields->type = 0;
-    tail = NULL;
-
-    regmatch.regprog = fmt_ptr->prog;
-    int r = vim_regexec(&regmatch, linebuf, (colnr_T)0);
-    fmt_ptr->prog = regmatch.regprog;
-    if (r) {
-      if ((idx == 'C' || idx == 'Z') && !qfl->qf_multiline) {
-        continue;
-      }
-      if (vim_strchr((char_u *)"EWI", idx) != NULL) {
-        fields->type = (char_u)idx;
-      } else {
-        fields->type = 0;
-      }
-      // Extract error message data from matched line.
-      // We check for an actual submatch, because "\[" and "\]" in
-      // the 'errorformat' may cause the wrong submatch to be used.
-      if ((i = (int)fmt_ptr->addr[0]) > 0) {  // %f
-        if (regmatch.startp[i] == NULL || regmatch.endp[i] == NULL) {
-          continue;
-        }
-        // Expand ~/file and $HOME/file to full path.
-        char_u c = *regmatch.endp[i];
-        *regmatch.endp[i] = NUL;
-        expand_env(regmatch.startp[i], fields->namebuf, CMDBUFFSIZE);
-        *regmatch.endp[i] = c;
-
-        if (vim_strchr((char_u *)"OPQ", idx) != NULL
-            && !os_path_exists(fields->namebuf)) {
-          continue;
-        }
-      }
-      if ((i = (int)fmt_ptr->addr[1]) > 0) {                  // %n
-        if (regmatch.startp[i] == NULL) {
-          continue;
-        }
-        fields->enr = (int)atol((char *)regmatch.startp[i]);
-      }
-      if ((i = (int)fmt_ptr->addr[2]) > 0) {                  // %l
-        if (regmatch.startp[i] == NULL) {
-          continue;
-        }
-        fields->lnum = atol((char *)regmatch.startp[i]);
-      }
-      if ((i = (int)fmt_ptr->addr[3]) > 0) {                  // %c
-        if (regmatch.startp[i] == NULL) {
-          continue;
-        }
-        fields->col = (int)atol((char *)regmatch.startp[i]);
-      }
-      if ((i = (int)fmt_ptr->addr[4]) > 0) {                  // %t
-        if (regmatch.startp[i] == NULL) {
-          continue;
-        }
-        fields->type = *regmatch.startp[i];
-      }
-      if (fmt_ptr->flags == '+' && !qfl->qf_multiscan) {      // %+
-        if (linelen >= fields->errmsglen) {
-          // linelen + null terminator
-          fields->errmsg = xrealloc(fields->errmsg, linelen + 1);
-          fields->errmsglen = linelen + 1;
-        }
-        STRLCPY(fields->errmsg, linebuf, linelen + 1);
-      } else if ((i = (int)fmt_ptr->addr[5]) > 0) {           // %m
-        if (regmatch.startp[i] == NULL || regmatch.endp[i] == NULL) {
-          continue;
-        }
-        len = (size_t)(regmatch.endp[i] - regmatch.startp[i]);
-        if (len >= fields->errmsglen) {
-          // len + null terminator
-          fields->errmsg = xrealloc(fields->errmsg, len + 1);
-          fields->errmsglen = len + 1;
-        }
-        STRLCPY(fields->errmsg, regmatch.startp[i], len + 1);
-      }
-      if ((i = (int)fmt_ptr->addr[6]) > 0) {                  // %r
-        if (regmatch.startp[i] == NULL) {
-          continue;
-        }
-        tail = regmatch.startp[i];
-      }
-      if ((i = (int)fmt_ptr->addr[7]) > 0) {                  // %p
-        char_u      *match_ptr;
-
-        if (regmatch.startp[i] == NULL || regmatch.endp[i] == NULL) {
-          continue;
-        }
-        fields->col = 0;
-        for (match_ptr = regmatch.startp[i];
-             match_ptr != regmatch.endp[i]; match_ptr++) {
-          fields->col++;
-          if (*match_ptr == TAB) {
-            fields->col += 7;
-            fields->col -= fields->col % 8;
-          }
-        }
-        fields->col++;
-        fields->use_viscol = true;
-      }
-      if ((i = (int)fmt_ptr->addr[8]) > 0) {                  // %v
-        if (regmatch.startp[i] == NULL) {
-          continue;
-        }
-        fields->col = (int)atol((char *)regmatch.startp[i]);
-        fields->use_viscol = true;
-      }
-      if ((i = (int)fmt_ptr->addr[9]) > 0) {                  // %s
-        if (regmatch.startp[i] == NULL || regmatch.endp[i] == NULL) {
-          continue;
-        }
-        len = (size_t)(regmatch.endp[i] - regmatch.startp[i]);
-        if (len > CMDBUFFSIZE - 5) {
-          len = CMDBUFFSIZE - 5;
-        }
-        STRCPY(fields->pattern, "^\\V");
-        xstrlcat((char *)fields->pattern, (char *)regmatch.startp[i],
-                 CMDBUFFSIZE+1);
-        fields->pattern[len + 3] = '\\';
-        fields->pattern[len + 4] = '$';
-        fields->pattern[len + 5] = NUL;
-      }
+    if (status == QF_OK) {
       break;
     }
   }
@@ -882,30 +758,16 @@ restofline:
 
   if (fmt_ptr == NULL || idx == 'D' || idx == 'X') {
     if (fmt_ptr != NULL) {
-      if (idx == 'D') {                               // enter directory
-        if (*fields->namebuf == NUL) {
-          EMSG(_("E379: Missing or empty directory name"));
-          return QF_FAIL;
-        }
-        qfl->qf_directory = qf_push_dir(fields->namebuf, &qfl->qf_dir_stack,
-                                        false);
-        if (qfl->qf_directory == NULL) {
-          return QF_FAIL;
-        }
-      } else if (idx == 'X') {                        // leave directory
-        qfl->qf_directory = qf_pop_dir(&qfl->qf_dir_stack);
+      // 'D' and 'X' directory specifiers.
+      status = qf_parse_dir_pfx(idx, fields, qfl);
+      if (status != QF_OK) {
+        return status;
       }
     }
-    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;
+    status = qf_parse_line_nomatch(linebuf, linelen, fields);
+    if (status != QF_OK) {
+      return status;
     }
-    // copy whole line to error message
-    STRLCPY(fields->errmsg, linebuf, linelen + 1);
     if (fmt_ptr == NULL) {
       qfl->qf_multiline = qfl->qf_multiignore = false;
     }
@@ -918,63 +780,17 @@ restofline:
     if (vim_strchr((char_u *)"AEWI", idx) != NULL) {
       qfl->qf_multiline = true;     // start of a multi-line message
       qfl->qf_multiignore = false;  // reset continuation
-    } else if (vim_strchr((char_u *)"CZ", idx)
-               != NULL) {  // continuation of multi-line msg
-      if (!qfl->qf_multiignore) {
-        qfline_T *qfprev = qfl->qf_last;
-        if (qfprev == NULL) {
-          return QF_FAIL;
-        }
-        if (*fields->errmsg) {
-          size_t textlen = STRLEN(qfprev->qf_text);
-          qfprev->qf_text = xrealloc(qfprev->qf_text,
-                                     textlen + STRLEN(fields->errmsg) + 2);
-          qfprev->qf_text[textlen] = '\n';
-          STRCPY(qfprev->qf_text + textlen + 1, fields->errmsg);
-        }
-        if (qfprev->qf_nr == -1) {
-          qfprev->qf_nr = fields->enr;
-        }
-        if (vim_isprintc(fields->type) && !qfprev->qf_type) {
-          qfprev->qf_type = fields->type;  // only printable chars allowed
-        }
-        if (!qfprev->qf_lnum) {
-          qfprev->qf_lnum = fields->lnum;
-        }
-        if (!qfprev->qf_col) {
-          qfprev->qf_col = fields->col;
-        }
-        qfprev->qf_viscol = fields->use_viscol;
-        if (!qfprev->qf_fnum) {
-          qfprev->qf_fnum = qf_get_fnum(qi, qf_idx, qfl->qf_directory,
-                                        *fields->namebuf || qfl->qf_directory
-                                        ? fields->namebuf
-                                        : qfl->qf_currfile && fields->valid
-                                        ? qfl->qf_currfile : 0);
-        }
+    } else if (vim_strchr((char_u *)"CZ", idx) != NULL) {
+      // continuation of multi-line msg
+      status = qf_parse_multiline_pfx(qi, qf_idx, idx, qfl, fields);
+      if (status != QF_OK) {
+        return status;
       }
-      if (idx == 'Z') {
-        qfl->qf_multiline = qfl->qf_multiignore = false;
-      }
-
-      line_breakcheck();
-      return QF_IGNORE_LINE;
     } else if (vim_strchr((char_u *)"OPQ", idx) != NULL) {
       // global file names
-      fields->valid = false;
-      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') {
-          qfl->qf_currfile = qf_pop_dir(&qfl->qf_file_stack);
-        }
-        *fields->namebuf = NUL;
-        if (tail && *tail) {
-          STRMOVE(IObuff, skipwhite(tail));
-          qfl->qf_multiscan = true;
-          goto restofline;
-        }
+      status = qf_parse_file_pfx(idx, fields, qfl, tail);
+      if (status == QF_MULTISCAN) {
+        goto restofline;
       }
     }
     if (fmt_ptr->flags == '-') {  // generally exclude this line
@@ -1034,6 +850,7 @@ qf_init_ext(
   }
 
   fields.namebuf = xmalloc(CMDBUFFSIZE + 1);
+  fields.module = xmalloc(CMDBUFFSIZE + 1);
   fields.errmsglen = CMDBUFFSIZE + 1;
   fields.errmsg = xmalloc(fields.errmsglen);
   fields.pattern = xmalloc(CMDBUFFSIZE + 1);
@@ -1128,6 +945,7 @@ qf_init_ext(
                      (*fields.namebuf || qfl->qf_directory)
                      ? fields.namebuf : ((qfl->qf_currfile && fields.valid)
                                          ? qfl->qf_currfile : (char_u *)NULL),
+                     fields.module,
                      0,
                      fields.errmsg,
                      fields.lnum,
@@ -1172,6 +990,7 @@ qf_init_end:
     fclose(state.fd);
   }
   xfree(fields.namebuf);
+  xfree(fields.module);
   xfree(fields.errmsg);
   xfree(fields.pattern);
   xfree(state.growbuf);
@@ -1187,6 +1006,8 @@ qf_init_end:
   return retval;
 }
 
+/// Set the title of the specified quickfix list. Frees the previous title.
+/// Prepends ':' to the title.
 static void qf_store_title(qf_info_T *qi, int qf_idx, char_u *title)
 {
   xfree(qi->qf_lists[qf_idx].qf_title);
@@ -1197,10 +1018,23 @@ static void qf_store_title(qf_info_T *qi, int qf_idx, char_u *title)
     char_u *p = xmallocz(len);
 
     qi->qf_lists[qf_idx].qf_title = p;
-    snprintf((char *)p, len + 1, ":%s", (char *)title);
+    xstrlcpy((char *)p, (char *)title, len + 1);
   }
 }
 
+/// The title of a quickfix/location list is set, by default, to the command
+/// that created the quickfix list with the ":" prefix.
+/// Create a quickfix list title string by prepending ":" to a user command.
+/// Returns a pointer to a static buffer with the title.
+static char_u * qf_cmdtitle(char_u *cmd)
+{
+  static char_u qftitle_str[IOSIZE];
+
+  snprintf((char *)qftitle_str, IOSIZE, ":%s", (char *)cmd);
+
+  return qftitle_str;
+}
+
 // Prepare for adding a new quickfix list. If the current list is in the
 // middle of the stack, then all the following lists are freed and then
 // the new list is added.
@@ -1230,9 +1064,301 @@ static void qf_new_list(qf_info_T *qi, char_u *qf_title)
   qi->qf_lists[qi->qf_curlist].qf_id = ++last_qf_id;
 }
 
-/*
- * Free a location list
- */
+/// Parse the error format matches in 'regmatch' and set the values in 'fields'.
+/// fmt_ptr contains the 'efm' format specifiers/prefixes that have a match.
+/// Returns QF_OK if all the matches are successfully parsed. On failure,
+/// returns QF_FAIL or QF_NOMEM.
+static int qf_parse_match(char_u *linebuf, size_t linelen, efm_T *fmt_ptr,
+                          regmatch_T *regmatch, qffields_T *fields,
+                          int qf_multiline, int qf_multiscan, char_u **tail)
+{
+  char_u idx = fmt_ptr->prefix;
+  int i;
+  size_t len;
+
+  if ((idx == 'C' || idx == 'Z') && !qf_multiline) {
+    return QF_FAIL;
+  }
+  if (vim_strchr((char_u *)"EWI", idx) != NULL) {
+    fields->type = idx;
+  } else {
+    fields->type = 0;
+  }
+
+  // Extract error message data from matched line.
+  // We check for an actual submatch, because "\[" and "\]" in
+  // the 'errorformat' may cause the wrong submatch to be used.
+  if ((i = (int)fmt_ptr->addr[0]) > 0) {  // %f
+    if (regmatch->startp[i] == NULL || regmatch->endp[i] == NULL) {
+      return QF_FAIL;
+    }
+
+    // Expand ~/file and $HOME/file to full path.
+    char_u c = *regmatch->endp[i];
+    *regmatch->endp[i] = NUL;
+    expand_env(regmatch->startp[i], fields->namebuf, CMDBUFFSIZE);
+    *regmatch->endp[i] = c;
+
+    if (vim_strchr((char_u *)"OPQ", idx) != NULL
+        && !os_path_exists(fields->namebuf)) {
+      return QF_FAIL;
+    }
+  }
+  if ((i = (int)fmt_ptr->addr[1]) > 0) {  // %n
+    if (regmatch->startp[i] == NULL) {
+      return QF_FAIL;
+    }
+    fields->enr = (int)atol((char *)regmatch->startp[i]);
+  }
+  if ((i = (int)fmt_ptr->addr[2]) > 0) {  // %l
+    if (regmatch->startp[i] == NULL) {
+      return QF_FAIL;
+    }
+    fields->lnum = atol((char *)regmatch->startp[i]);
+  }
+  if ((i = (int)fmt_ptr->addr[3]) > 0) {  // %c
+    if (regmatch->startp[i] == NULL) {
+      return QF_FAIL;
+    }
+    fields->col = (int)atol((char *)regmatch->startp[i]);
+  }
+  if ((i = (int)fmt_ptr->addr[4]) > 0) {  // %t
+    if (regmatch->startp[i] == NULL) {
+      return QF_FAIL;
+    }
+    fields->type = *regmatch->startp[i];
+  }
+  if (fmt_ptr->flags == '+' && !qf_multiscan) {  // %+
+    if (linelen >= fields->errmsglen) {
+      // linelen + null terminator
+      fields->errmsg = xrealloc(fields->errmsg, linelen + 1);
+      fields->errmsglen = linelen + 1;
+    }
+    STRLCPY(fields->errmsg, linebuf, linelen + 1);
+  } else if ((i = (int)fmt_ptr->addr[5]) > 0) {  // %m
+    if (regmatch->startp[i] == NULL || regmatch->endp[i] == NULL) {
+      return QF_FAIL;
+    }
+    len = (size_t)(regmatch->endp[i] - regmatch->startp[i]);
+    if (len >= fields->errmsglen) {
+      // len + null terminator
+      fields->errmsg = xrealloc(fields->errmsg, len + 1);
+      fields->errmsglen = len + 1;
+    }
+    STRLCPY(fields->errmsg, regmatch->startp[i], len + 1);
+  }
+  if ((i = (int)fmt_ptr->addr[6]) > 0) {  // %r
+    if (regmatch->startp[i] == NULL) {
+      return QF_FAIL;
+    }
+    *tail = regmatch->startp[i];
+  }
+  if ((i = (int)fmt_ptr->addr[7]) > 0) {  // %p
+    if (regmatch->startp[i] == NULL || regmatch->endp[i] == NULL) {
+      return QF_FAIL;
+    }
+    fields->col = 0;
+    char_u *match_ptr;
+    for (match_ptr = regmatch->startp[i]; match_ptr != regmatch->endp[i];
+         match_ptr++) {
+      fields->col++;
+      if (*match_ptr == TAB) {
+        fields->col += 7;
+        fields->col -= fields->col % 8;
+      }
+    }
+    fields->col++;
+    fields->use_viscol = true;
+  }
+  if ((i = (int)fmt_ptr->addr[8]) > 0) {  // %v
+    if (regmatch->startp[i] == NULL) {
+      return QF_FAIL;
+    }
+    fields->col = (int)atol((char *)regmatch->startp[i]);
+    fields->use_viscol = true;
+  }
+  if ((i = (int)fmt_ptr->addr[9]) > 0) {  // %s
+    if (regmatch->startp[i] == NULL || regmatch->endp[i] == NULL) {
+      return QF_FAIL;
+    }
+    len = (size_t)(regmatch->endp[i] - regmatch->startp[i]);
+    if (len > CMDBUFFSIZE - 5) {
+      len = CMDBUFFSIZE - 5;
+    }
+    STRCPY(fields->pattern, "^\\V");
+    STRNCAT(fields->pattern, regmatch->startp[i], len);
+    fields->pattern[len + 3] = '\\';
+    fields->pattern[len + 4] = '$';
+    fields->pattern[len + 5] = NUL;
+  }
+  if ((i = (int)fmt_ptr->addr[10]) > 0) {  // %o
+    if (regmatch->startp[i] == NULL || regmatch->endp[i] == NULL) {
+      return QF_FAIL;
+    }
+    len = (size_t)(regmatch->endp[i] - regmatch->startp[i]);
+    if (len > CMDBUFFSIZE) {
+      len = CMDBUFFSIZE;
+    }
+    STRNCAT(fields->module, regmatch->startp[i], len);
+  }
+
+  return QF_OK;
+}
+
+/// Parse an error line in 'linebuf' using a single error format string in
+/// 'fmt_ptr->prog' and return the matching values in 'fields'.
+/// Returns QF_OK if the efm format matches completely and the fields are
+/// successfully copied. Otherwise returns QF_FAIL or QF_NOMEM.
+static int qf_parse_get_fields(char_u *linebuf, size_t linelen, efm_T *fmt_ptr,
+                               qffields_T *fields, int qf_multiline,
+                               int qf_multiscan, char_u **tail)
+{
+  regmatch_T regmatch;
+  int status = QF_FAIL;
+  int r;
+
+  if (qf_multiscan && vim_strchr((char_u *)"OPQ", fmt_ptr->prefix) == NULL) {
+    return QF_FAIL;
+  }
+
+  fields->namebuf[0] = NUL;
+  fields->module[0] = NUL;
+  fields->pattern[0] = NUL;
+  if (!qf_multiscan) {
+    fields->errmsg[0] = NUL;
+  }
+  fields->lnum = 0;
+  fields->col = 0;
+  fields->use_viscol = false;
+  fields->enr = -1;
+  fields->type = 0;
+  *tail = NULL;
+
+  // Always ignore case when looking for a matching error.
+  regmatch.rm_ic = true;
+  regmatch.regprog = fmt_ptr->prog;
+  r = vim_regexec(&regmatch, linebuf, (colnr_T)0);
+  fmt_ptr->prog = regmatch.regprog;
+  if (r) {
+    status = qf_parse_match(linebuf, linelen, fmt_ptr, &regmatch, fields,
+                            qf_multiline, qf_multiscan, tail);
+  }
+
+  return status;
+}
+
+/// Parse directory error format prefixes (%D and %X).
+/// Push and pop directories from the directory stack when scanning directory
+/// names.
+static int qf_parse_dir_pfx(int idx, qffields_T *fields, qf_list_T *qfl)
+{
+  if (idx == 'D') {  // enter directory
+    if (*fields->namebuf == NUL) {
+      EMSG(_("E379: Missing or empty directory name"));
+      return QF_FAIL;
+    }
+    qfl->qf_directory = qf_push_dir(fields->namebuf, &qfl->qf_dir_stack, false);
+    if (qfl->qf_directory == NULL) {
+      return QF_FAIL;
+    }
+  } else if (idx == 'X') {  // leave directory
+    qfl->qf_directory = qf_pop_dir(&qfl->qf_dir_stack);
+  }
+
+  return QF_OK;
+}
+
+/// Parse global file name error format prefixes (%O, %P and %Q).
+static int qf_parse_file_pfx(int idx, qffields_T *fields, qf_list_T *qfl,
+                             char_u *tail)
+{
+  fields->valid = false;
+  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') {
+      qfl->qf_currfile = qf_pop_dir(&qfl->qf_file_stack);
+    }
+    *fields->namebuf = NUL;
+    if (tail && *tail) {
+      STRMOVE(IObuff, skipwhite(tail));
+      qfl->qf_multiscan = true;
+      return QF_MULTISCAN;
+    }
+  }
+
+  return QF_OK;
+}
+
+/// Parse a non-error line (a line which doesn't match any of the error
+/// format in 'efm').
+static int qf_parse_line_nomatch(char_u *linebuf, size_t linelen,
+                                 qffields_T *fields)
+{
+  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;
+}
+
+/// Parse multi-line error format prefixes (%C and %Z)
+static int qf_parse_multiline_pfx(qf_info_T *qi, int qf_idx, int idx,
+                                  qf_list_T *qfl, qffields_T *fields)
+{
+  if (!qfl->qf_multiignore) {
+    qfline_T *qfprev = qfl->qf_last;
+
+    if (qfprev == NULL) {
+      return QF_FAIL;
+    }
+    if (*fields->errmsg && !qfl->qf_multiignore) {
+      size_t textlen = strlen((char *)qfprev->qf_text);
+      size_t errlen  = strlen((char *)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);
+    }
+    if (qfprev->qf_nr == -1) {
+      qfprev->qf_nr = fields->enr;
+    }
+    if (vim_isprintc(fields->type) && !qfprev->qf_type) {
+      // only printable chars allowed
+      qfprev->qf_type = fields->type;
+    }
+
+    if (!qfprev->qf_lnum) {
+      qfprev->qf_lnum = fields->lnum;
+    }
+    if (!qfprev->qf_col) {
+      qfprev->qf_col = fields->col;
+    }
+    qfprev->qf_viscol = fields->use_viscol;
+    if (!qfprev->qf_fnum) {
+      qfprev->qf_fnum = qf_get_fnum(qi, qf_idx, qfl->qf_directory,
+                                    *fields->namebuf || qfl->qf_directory
+                                    ? fields->namebuf
+                                    : qfl->qf_currfile && fields->valid
+                                    ? qfl->qf_currfile : 0);
+    }
+  }
+  if (idx == 'Z') {
+    qfl->qf_multiline = qfl->qf_multiignore = false;
+  }
+  line_breakcheck();
+
+  return QF_IGNORE_LINE;
+}
+
+/// Free a location list.
 static void ll_free_all(qf_info_T **pqi)
 {
   int i;
@@ -1252,6 +1378,7 @@ static void ll_free_all(qf_info_T **pqi)
   }
 }
 
+/// Free all the quickfix/location lists in the stack.
 void qf_free_all(win_T *wp)
 {
   int i;
@@ -1273,6 +1400,7 @@ void qf_free_all(win_T *wp)
 /// @param  qf_idx   list index
 /// @param  dir      optional directory name
 /// @param  fname    file name or NULL
+/// @param  module   module name or NULL
 /// @param  bufnum   buffer number or zero
 /// @param  mesg     message
 /// @param  lnum     line number
@@ -1285,9 +1413,9 @@ void qf_free_all(win_T *wp)
 ///
 /// @returns OK or FAIL.
 static int qf_add_entry(qf_info_T *qi, int qf_idx, char_u *dir, char_u *fname,
-                        int bufnum, char_u *mesg, long lnum, int col,
-                        char_u vis_col, char_u *pattern, int nr, char_u type,
-                        char_u valid)
+                        char_u *module, int bufnum, char_u *mesg, long lnum,
+                        int col, char_u vis_col, char_u *pattern, int nr,
+                        char_u type, char_u valid)
 {
   qfline_T *qfp = xmalloc(sizeof(qfline_T));
   qfline_T **lastp;  // pointer to qf_last or NULL
@@ -1312,6 +1440,14 @@ static int qf_add_entry(qf_info_T *qi, int qf_idx, char_u *dir, char_u *fname,
   } else {
     qfp->qf_pattern = vim_strsave(pattern);
   }
+  if (module == NULL || *module == NUL) {
+    qfp->qf_module = NULL;
+  } else if ((qfp->qf_module = vim_strsave(module)) == NULL) {
+    xfree(qfp->qf_text);
+    xfree(qfp->qf_pattern);
+    xfree(qfp);
+    return QF_FAIL;
+  }
   qfp->qf_nr = nr;
   if (type != 1 && !vim_isprintc(type))   /* only printable chars allowed */
     type = 0;
@@ -1443,6 +1579,7 @@ void copy_loclist(win_T *from, win_T *to)
                          to->w_llist->qf_curlist,
                          NULL,
                          NULL,
+                         from_qfp->qf_module,
                          0,
                          from_qfp->qf_text,
                          from_qfp->qf_lnum,
@@ -1473,6 +1610,7 @@ void copy_loclist(win_T *from, win_T *to)
 
     // Assign a new ID for the location list
     to_qfl->qf_id = ++last_qf_id;
+    to_qfl->qf_changedtick = 0L;
 
     /* When no valid entries are present in the list, qf_ptr points to
      * the first item in the list */
@@ -1699,6 +1837,27 @@ static char_u *qf_guess_filepath(qf_info_T *qi, int qf_idx, char_u *filename)
   return ds_ptr == NULL ? NULL : ds_ptr->dirname;
 }
 
+/// Returns true, if a quickfix/location list with the given identifier exists.
+static bool qflist_valid(win_T *wp, unsigned int qf_id)
+{
+  qf_info_T *qi = &ql_info;
+
+  if (wp) {
+    qi = GET_LOC_LIST(wp);
+    if (!qi) {
+      return false;
+    }
+  }
+
+  for (int i = 0; i < qi->qf_listcount; i++) {
+    if (qi->qf_lists[i].qf_id == qf_id) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 /// When loading a file from the quickfix, the auto commands may modify it.
 /// This may invalidate the current quickfix entry.  This function checks
 /// whether a entry is still present in the quickfix.
@@ -2050,19 +2209,28 @@ static int qf_jump_edit_buffer(qf_info_T *qi, qfline_T *qf_ptr, int forceit,
     }
   } else {
     int old_qf_curlist = qi->qf_curlist;
+    unsigned save_qfid = qi->qf_lists[qi->qf_curlist].qf_id;
 
     retval = buflist_getfile(qf_ptr->qf_fnum, (linenr_T)1,
                              GETF_SETMARK | GETF_SWITCH, forceit);
-    if (qi != &ql_info && !win_valid_any_tab(oldwin)) {
-      EMSG(_("E924: Current window was closed"));
-      *abort = true;
-      *opened_window = false;
+
+    if (qi != &ql_info) {
+      // Location list. Check whether the associated window is still
+      // present and the list is still valid.
+      if (!win_valid_any_tab(oldwin)) {
+        EMSG(_("E924: Current window was closed"));
+        *abort = true;
+        *opened_window = false;
+      } else if (!qflist_valid(oldwin, save_qfid)) {
+        EMSG(_(e_loc_list_changed));
+        *abort = true;
+      }
     } else if (old_qf_curlist != qi->qf_curlist
                || !is_qf_entry_present(qi, qf_ptr)) {
       if (qi == &ql_info) {
         EMSG(_("E925: Current quickfix was changed"));
       } else {
-        EMSG(_("E926: Current location list was changed"));
+        EMSG(_(e_loc_list_changed));
       }
       *abort = true;
     }
@@ -2360,17 +2528,22 @@ void qf_list(exarg_T *eap)
         break;
 
       fname = NULL;
-      if (qfp->qf_fnum != 0
-          && (buf = buflist_findnr(qfp->qf_fnum)) != NULL) {
-        fname = buf->b_fname;
-        if (qfp->qf_type == 1)          /* :helpgrep */
-          fname = path_tail(fname);
+      if (qfp->qf_module != NULL && *qfp->qf_module != NUL) {
+        vim_snprintf((char *)IObuff, IOSIZE, "%2d %s", i,
+                     (char *)qfp->qf_module);
+      } else {
+        if (qfp->qf_fnum != 0 && (buf = buflist_findnr(qfp->qf_fnum)) != NULL) {
+          fname = buf->b_fname;
+          if (qfp->qf_type == 1) {  // :helpgrep
+            fname = path_tail(fname);
+          }
+        }
+        if (fname == NULL) {
+          snprintf((char *)IObuff, IOSIZE, "%2d", i);
+        } else {
+          vim_snprintf((char *)IObuff, IOSIZE, "%2d %s", i, (char *)fname);
+        }
       }
-      if (fname == NULL)
-        sprintf((char *)IObuff, "%2d", i);
-      else
-        vim_snprintf((char *)IObuff, IOSIZE, "%2d %s",
-            i, (char *)fname);
       msg_outtrans_attr(IObuff, i == qi->qf_lists[qi->qf_curlist].qf_index
                         ? HL_ATTR(HLF_QFL) : HL_ATTR(HLF_D));
       if (qfp->qf_lnum == 0) {
@@ -2431,6 +2604,8 @@ static void qf_fmt_text(char_u *text, char_u *buf, int bufsize)
   buf[i] = NUL;
 }
 
+/// Display information (list number, list size and the title) about a
+/// quickfix/location list.
 static void qf_msg(qf_info_T *qi, int which, char *lead)
 {
   char *title = (char *)qi->qf_lists[which].qf_title;
@@ -2500,6 +2675,7 @@ void qf_age(exarg_T *eap)
   qf_update_buffer(qi, NULL);
 }
 
+/// Display the information about all the quickfix/location lists in the stack.
 void qf_history(exarg_T *eap)
 {
   qf_info_T *qi = &ql_info;
@@ -2531,9 +2707,10 @@ static void qf_free_items(qf_info_T *qi, int idx)
     qfp = qfl->qf_start;
     qfpnext = qfp->qf_next;
     if (!stop) {
+      xfree(qfp->qf_module);
       xfree(qfp->qf_text);
-      stop = (qfp == qfpnext);
       xfree(qfp->qf_pattern);
+      stop = (qfp == qfpnext);
       xfree(qfp);
       if (stop) {
         // Somehow qf_count may have an incorrect value, set it to 1
@@ -2575,6 +2752,7 @@ static void qf_free(qf_info_T *qi, int idx)
   tv_free(qfl->qf_ctx);
   qfl->qf_ctx = NULL;
   qfl->qf_id = 0;
+  qfl->qf_changedtick = 0L;
 }
 
 /*
@@ -2944,10 +3122,8 @@ static int is_qf_win(win_T *win, qf_info_T *qi)
   return FALSE;
 }
 
-/*
- * Find a window displaying the quickfix/location list 'qi'
- * Searches in only the windows opened in the current tab.
- */
+/// Find a window displaying the quickfix/location list 'qi'
+/// Only searches in the current tabpage.
 static win_T *qf_find_win(qf_info_T *qi)
 {
   FOR_ALL_WINDOWS_IN_TAB(win, curtab) {
@@ -3075,9 +3251,12 @@ static void qf_fill_buffer(qf_info_T *qi, buf_T *buf, qfline_T *old_last)
       lnum = buf->b_ml.ml_line_count;
     }
     while (lnum < qi->qf_lists[qi->qf_curlist].qf_count) {
-      if (qfp->qf_fnum != 0
-          && (errbuf = buflist_findnr(qfp->qf_fnum)) != NULL
-          && errbuf->b_fname != NULL) {
+      if (qfp->qf_module != NULL) {
+