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

1 files changed, 319 insertions, 299 deletions

diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index 30898981de..9da9d6199e 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -6,62 +6,72 @@
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <iconv.h>
 #include <inttypes.h>
+#include <limits.h>
 #include <stdbool.h>
+#include <stdio.h>
 #include <string.h>
+#include <sys/stat.h>
+#include <uv.h>
 
-#include "nvim/api/private/helpers.h"
+#include "auto/config.h"
 #include "nvim/ascii.h"
+#include "nvim/autocmd.h"
 #include "nvim/buffer.h"
+#include "nvim/buffer_defs.h"
 #include "nvim/buffer_updates.h"
 #include "nvim/change.h"
-#include "nvim/charset.h"
 #include "nvim/cursor.h"
 #include "nvim/diff.h"
 #include "nvim/drawscreen.h"
 #include "nvim/edit.h"
 #include "nvim/eval.h"
-#include "nvim/eval/typval.h"
-#include "nvim/eval/userfunc.h"
 #include "nvim/ex_cmds.h"
-#include "nvim/ex_docmd.h"
 #include "nvim/ex_eval.h"
 #include "nvim/fileio.h"
 #include "nvim/fold.h"
-#include "nvim/func_attr.h"
 #include "nvim/garray.h"
 #include "nvim/getchar.h"
-#include "nvim/hashtab.h"
+#include "nvim/gettext.h"
+#include "nvim/globals.h"
+#include "nvim/highlight_defs.h"
 #include "nvim/iconv.h"
 #include "nvim/input.h"
+#include "nvim/log.h"
+#include "nvim/macros.h"
 #include "nvim/mbyte.h"
 #include "nvim/memfile.h"
 #include "nvim/memline.h"
 #include "nvim/memory.h"
 #include "nvim/message.h"
 #include "nvim/move.h"
-#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/os_defs.h"
 #include "nvim/os/time.h"
-#include "nvim/os_unix.h"
 #include "nvim/path.h"
-#include "nvim/quickfix.h"
+#include "nvim/pos.h"
 #include "nvim/regexp.h"
-#include "nvim/search.h"
+#include "nvim/screen.h"
 #include "nvim/sha256.h"
 #include "nvim/shada.h"
-#include "nvim/state.h"
 #include "nvim/strings.h"
 #include "nvim/types.h"
 #include "nvim/ui.h"
-#include "nvim/ui_compositor.h"
 #include "nvim/undo.h"
 #include "nvim/vim.h"
-#include "nvim/window.h"
+
+#if defined(HAVE_FLOCK) && defined(HAVE_DIRFD)
+# include <dirent.h>
+# include <sys/file.h>
+#endif
+
+#ifdef OPEN_CHR_FILES
+# include "nvim/charset.h"
+#endif
 
 #define BUFSIZE         8192    // size of normal write buffer
 #define SMBUFSIZE       256     // size of emergency write buffer
@@ -72,15 +82,17 @@
 #endif
 
 #define HAS_BW_FLAGS
-#define FIO_LATIN1     0x01    // convert Latin1
-#define FIO_UTF8       0x02    // convert UTF-8
-#define FIO_UCS2       0x04    // convert UCS-2
-#define FIO_UCS4       0x08    // convert UCS-4
-#define FIO_UTF16      0x10    // convert UTF-16
-#define FIO_ENDIAN_L   0x80    // little endian
-#define FIO_NOCONVERT  0x2000  // skip encoding conversion
-#define FIO_UCSBOM     0x4000  // check for BOM at start of file
-#define FIO_ALL        (-1)    // allow all formats
+enum {
+  FIO_LATIN1 = 0x01,       // convert Latin1
+  FIO_UTF8 = 0x02,         // convert UTF-8
+  FIO_UCS2 = 0x04,         // convert UCS-2
+  FIO_UCS4 = 0x08,         // convert UCS-4
+  FIO_UTF16 = 0x10,        // convert UTF-16
+  FIO_ENDIAN_L = 0x80,     // little endian
+  FIO_NOCONVERT = 0x2000,  // skip encoding conversion
+  FIO_UCSBOM = 0x4000,     // check for BOM at start of file
+  FIO_ALL = -1,            // allow all formats
+};
 
 // When converting, a read() or write() may leave some bytes to be converted
 // for the next call.  The value is guessed...
@@ -93,7 +105,7 @@
 // Structure to pass arguments from buf_write() to buf_write_bytes().
 struct bw_info {
   int bw_fd;                     // file descriptor
-  char_u *bw_buf;           // buffer with data to be written
+  char *bw_buf;                  // buffer with data to be written
   int bw_len;                    // length of data
 #ifdef HAS_BW_FLAGS
   int bw_flags;                  // FIO_ flags
@@ -101,14 +113,12 @@ struct bw_info {
   char_u bw_rest[CONV_RESTLEN];  // not converted bytes
   int bw_restlen;                // nr of bytes in bw_rest[]
   int bw_first;                  // first write call
-  char_u *bw_conv_buf;           // buffer for writing converted chars
+  char *bw_conv_buf;             // buffer for writing converted chars
   size_t bw_conv_buflen;         // size of bw_conv_buf
   int bw_conv_error;             // set for conversion error
   linenr_T bw_conv_error_lnum;   // first line with error or zero
   linenr_T bw_start_lnum;        // line number at start of buffer
-#ifdef HAVE_ICONV
   iconv_t bw_iconv_fd;           // descriptor for iconv() or -1
-#endif
 };
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
@@ -126,7 +136,7 @@ void filemess(buf_T *buf, char *name, char *s, int attr)
   if (msg_silent != 0) {
     return;
   }
-  add_quoted_fname((char *)IObuff, IOSIZE - 100, buf, (const char *)name);
+  add_quoted_fname(IObuff, IOSIZE - 100, buf, (const char *)name);
   // Avoid an over-long translation to cause trouble.
   xstrlcat(IObuff, s, IOSIZE);
   // For the first message may have to start a new line.
@@ -143,7 +153,7 @@ void filemess(buf_T *buf, char *name, char *s, int attr)
   msg_scroll = msg_scroll_save;
   msg_scrolled_ign = true;
   // may truncate the message to avoid a hit-return prompt
-  msg_outtrans_attr(msg_may_trunc(false, (char *)IObuff), attr);
+  msg_outtrans_attr(msg_may_trunc(false, IObuff), attr);
   msg_clr_eos();
   ui_flush();
   msg_scrolled_ign = false;
@@ -236,11 +246,9 @@ int readfile(char *fname, char *sfname, linenr_T from, linenr_T lines_to_skip,
   char *fenc_next = NULL;        // next item in 'fencs' or NULL
   bool advance_fenc = false;
   long real_size = 0;
-#ifdef HAVE_ICONV
   iconv_t iconv_fd = (iconv_t)-1;       // descriptor for iconv() or -1
   bool did_iconv = false;               // true when iconv() failed and trying
                                         // 'charconvert' next
-#endif
   bool converted = false;                // true if conversion done
   bool notconverted = false;             // true if conversion wanted but it wasn't possible
   char conv_rest[CONV_RESTLEN];
@@ -266,7 +274,7 @@ int readfile(char *fname, char *sfname, linenr_T from, linenr_T lines_to_skip,
       && fname != NULL
       && vim_strchr(p_cpo, CPO_FNAMER) != NULL
       && !(flags & READ_DUMMY)) {
-    if (set_rw_fname((char_u *)fname, (char_u *)sfname) == FAIL) {
+    if (set_rw_fname(fname, sfname) == FAIL) {
       return FAIL;
     }
   }
@@ -476,7 +484,7 @@ int readfile(char *fname, char *sfname, linenr_T from, linenr_T lines_to_skip,
         }
       }
       if (!silent) {
-        if (dir_of_file_exists((char_u *)fname)) {
+        if (dir_of_file_exists(fname)) {
           filemess(curbuf, sfname, new_file_message(), 0);
         } else {
           filemess(curbuf, sfname, _("[New DIRECTORY]"), 0);
@@ -498,18 +506,17 @@ int readfile(char *fname, char *sfname, linenr_T from, linenr_T lines_to_skip,
         return FAIL;
       }
       return OK;                  // a new file is not an error
-    } else {
-      filemess(curbuf, sfname, ((fd == UV_EFBIG) ? _("[File too big]") :
+    }
+    filemess(curbuf, sfname, ((fd == UV_EFBIG) ? _("[File too big]") :
 #if defined(UNIX) && defined(EOVERFLOW)
-                                // libuv only returns -errno
-                                // in Unix and in Windows
-                                // open() does not set
-                                // EOVERFLOW
-                                (fd == -EOVERFLOW) ? _("[File too big]") :
+                              // libuv only returns -errno
+                              // in Unix and in Windows
+                              // open() does not set
+                              // EOVERFLOW
+                              (fd == -EOVERFLOW) ? _("[File too big]") :
 #endif
-                                _("[Permission Denied]")), 0);
-      curbuf->b_p_ro = true;                  // must use "w!" now
-    }
+                              _("[Permission Denied]")), 0);
+    curbuf->b_p_ro = true;                  // must use "w!" now
 
     return FAIL;
   }
@@ -524,6 +531,8 @@ int readfile(char *fname, char *sfname, linenr_T from, linenr_T lines_to_skip,
     // Don't change 'eol' if reading from buffer as it will already be
     // correctly set when reading stdin.
     if (!read_buffer) {
+      curbuf->b_p_eof = false;
+      curbuf->b_start_eof = false;
       curbuf->b_p_eol = true;
       curbuf->b_start_eol = true;
     }
@@ -766,13 +775,11 @@ retry:
     }
   }
 
-#ifdef HAVE_ICONV
   if (iconv_fd != (iconv_t)-1) {
     // aborted conversion with iconv(), close the descriptor
     iconv_close(iconv_fd);
     iconv_fd = (iconv_t)-1;
   }
-#endif
 
   if (advance_fenc) {
     // Try the next entry in 'fileencodings'.
@@ -822,32 +829,24 @@ retry:
       // appears not to handle this correctly.  This works just like
       // conversion to UTF-8 except how the resulting character is put in
       // the buffer.
-      fio_flags = get_fio_flags((char_u *)fenc);
+      fio_flags = get_fio_flags(fenc);
     }
 
-#ifdef HAVE_ICONV
     // Try using iconv() if we can't convert internally.
     if (fio_flags == 0
         && !did_iconv) {
-      iconv_fd = (iconv_t)my_iconv_open((char_u *)"utf-8", (char_u *)fenc);
+      iconv_fd = (iconv_t)my_iconv_open("utf-8", fenc);
     }
-#endif
 
     // Use the 'charconvert' expression when conversion is required
     // and we can't do it internally or with iconv().
     if (fio_flags == 0 && !read_stdin && !read_buffer && *p_ccv != NUL
-        && !read_fifo
-#ifdef HAVE_ICONV
-        && iconv_fd == (iconv_t)-1
-#endif
-        ) {
-#ifdef HAVE_ICONV
+        && !read_fifo && iconv_fd == (iconv_t)-1) {
       did_iconv = false;
-#endif
       // Skip conversion when it's already done (retry for wrong
       // "fileformat").
       if (tmpname == NULL) {
-        tmpname = (char *)readfile_charconvert((char_u *)fname, (char_u *)fenc, &fd);
+        tmpname = readfile_charconvert(fname, fenc, &fd);
         if (tmpname == NULL) {
           // Conversion failed.  Try another one.
           advance_fenc = true;
@@ -861,11 +860,7 @@ retry:
         }
       }
     } else {
-      if (fio_flags == 0
-#ifdef HAVE_ICONV
-          && iconv_fd == (iconv_t)-1
-#endif
-          ) {
+      if (fio_flags == 0 && iconv_fd == (iconv_t)-1) {
         // Conversion wanted but we can't.
         // Try the next conversion in 'fileencodings'
         advance_fenc = true;
@@ -948,12 +943,9 @@ retry:
         // ucs-4 to utf-8: 4 bytes become up to 6 bytes, size must be
         // multiple of 4
         real_size = (int)size;
-#ifdef HAVE_ICONV
         if (iconv_fd != (iconv_t)-1) {
           size = size / ICONV_MULT;
-        } else {
-#endif
-        if (fio_flags & FIO_LATIN1) {
+        } else if (fio_flags & FIO_LATIN1) {
           size = size / 2;
         } else if (fio_flags & (FIO_UCS2 | FIO_UTF16)) {
           size = (size * 2 / 3) & ~1;
@@ -962,9 +954,7 @@ retry:
         } else if (fio_flags == FIO_UCSBOM) {
           size = size / ICONV_MULT;  // worst case
         }
-#ifdef HAVE_ICONV
-      }
-#endif
+
         if (conv_restlen > 0) {
           // Insert unconverted bytes from previous line.
           memmove(ptr, conv_rest, (size_t)conv_restlen);  // -V614
@@ -984,7 +974,7 @@ retry:
             tlen = 0;
             for (;;) {
               p = (char_u *)ml_get(read_buf_lnum) + read_buf_col;
-              n = (int)STRLEN(p);
+              n = (int)strlen((char *)p);
               if ((int)tlen + n + 1 > size) {
                 // Filled up to "size", append partial line.
                 // Change NL to NUL to reverse the effect done
@@ -1036,11 +1026,7 @@ retry:
             // not be converted.  Truncated file?
 
             // When we did a conversion report an error.
-            if (fio_flags != 0
-#ifdef HAVE_ICONV
-                || iconv_fd != (iconv_t)-1
-#endif
-                ) {
+            if (fio_flags != 0 || iconv_fd != (iconv_t)-1) {
               if (can_retry) {
                 goto rewind_retry;
               }
@@ -1048,9 +1034,8 @@ retry:
                 conv_error = curbuf->b_ml.ml_line_count
                              - linecnt + 1;
               }
-            }
-            // Remember the first linenr with an illegal byte
-            else if (illegal_byte == 0) {
+            } else if (illegal_byte == 0) {
+              // Remember the first linenr with an illegal byte
               illegal_byte = curbuf->b_ml.ml_line_count
                              - linecnt + 1;
             }
@@ -1062,23 +1047,17 @@ retry:
               // character if we were converting; if we weren't,
               // leave the UTF8 checking code to do it, as it
               // works slightly differently.
-              if (bad_char_behavior != BAD_KEEP && (fio_flags != 0
-#ifdef HAVE_ICONV
-                                                    || iconv_fd != (iconv_t)-1
-#endif
-                                                    )) {
+              if (bad_char_behavior != BAD_KEEP && (fio_flags != 0 || iconv_fd != (iconv_t)-1)) {
                 while (conv_restlen > 0) {
                   *(--ptr) = (char)bad_char_behavior;
                   conv_restlen--;
                 }
               }
               fio_flags = 0;  // don't convert this
-#ifdef HAVE_ICONV
               if (iconv_fd != (iconv_t)-1) {
                 iconv_close(iconv_fd);
                 iconv_fd = (iconv_t)-1;
               }
-#endif
             }
           }
         }
@@ -1095,15 +1074,15 @@ retry:
               || (!curbuf->b_p_bomb
                   && tmpname == NULL
                   && (*fenc == 'u' || *fenc == NUL)))) {
-        char_u *ccname;
+        char *ccname;
         int blen = 0;
 
         // no BOM detection in a short file or in binary mode
         if (size < 2 || curbuf->b_p_bin) {
           ccname = NULL;
         } else {
-          ccname = check_for_bom((char_u *)ptr, size, &blen,
-                                 fio_flags == FIO_UCSBOM ? FIO_ALL : get_fio_flags((char_u *)fenc));
+          ccname = check_for_bom(ptr, size, &blen,
+                                 fio_flags == FIO_UCSBOM ? FIO_ALL : get_fio_flags(fenc));
         }
         if (ccname != NULL) {
           // Remove BOM from the text
@@ -1125,7 +1104,7 @@ retry:
             if (fenc_alloced) {
               xfree(fenc);
             }
-            fenc = (char *)ccname;
+            fenc = ccname;
             fenc_alloced = false;
           }
           // retry reading without getting new bytes or rewinding
@@ -1143,7 +1122,6 @@ retry:
         break;
       }
 
-#ifdef HAVE_ICONV
       if (iconv_fd != (iconv_t)-1) {
         // Attempt conversion of the read bytes to 'encoding' using iconv().
         const char *fromp = ptr;
@@ -1163,7 +1141,7 @@ retry:
             goto rewind_retry;
           }
           if (conv_error == 0) {
-            conv_error = readfile_linenr(linecnt, (char_u *)ptr, (char_u *)top);
+            conv_error = readfile_linenr(linecnt, ptr, top);
           }
 
           // Deal with a bad byte and continue with the next.
@@ -1181,7 +1159,7 @@ retry:
         if (from_size > 0) {
           // Some remaining characters, keep them for the next
           // round.
-          memmove(conv_rest, (char_u *)fromp, from_size);
+          memmove(conv_rest, fromp, from_size);
           conv_restlen = (int)from_size;
         }
 
@@ -1190,7 +1168,6 @@ retry:
         memmove(line_start, buffer, (size_t)linerest);
         size = (top - ptr);
       }
-#endif
 
       if (fio_flags != 0) {
         unsigned int u8c;
@@ -1275,7 +1252,7 @@ retry:
                   goto rewind_retry;
                 }
                 if (conv_error == 0) {
-                  conv_error = readfile_linenr(linecnt, (char_u *)ptr, p);
+                  conv_error = readfile_linenr(linecnt, ptr, (char *)p);
                 }
                 if (bad_char_behavior == BAD_DROP) {
                   continue;
@@ -1303,7 +1280,7 @@ retry:
                   goto rewind_retry;
                 }
                 if (conv_error == 0) {
-                  conv_error = readfile_linenr(linecnt, (char_u *)ptr, p);
+                  conv_error = readfile_linenr(linecnt, ptr, (char *)p);
                 }
                 if (bad_char_behavior == BAD_DROP) {
                   continue;
@@ -1344,7 +1321,7 @@ retry:
                   goto rewind_retry;
                 }
                 if (conv_error == 0) {
-                  conv_error = readfile_linenr(linecnt, (char_u *)ptr, p);
+                  conv_error = readfile_linenr(linecnt, ptr, (char *)p);
                 }
                 if (bad_char_behavior == BAD_DROP) {
                   continue;
@@ -1382,7 +1359,7 @@ retry:
             // an incomplete character at the end though, the next
             // read() will get the next bytes, we'll check it
             // then.
-            l = utf_ptr2len_len(p, todo);
+            l = utf_ptr2len_len((char *)p, todo);
             if (l > todo && !incomplete_tail) {
               // Avoid retrying with a different encoding when
               // a truncated file is more likely, or attempting
@@ -1408,15 +1385,15 @@ retry:
               if (can_retry && !incomplete_tail) {
                 break;
               }
-#ifdef HAVE_ICONV
+
               // When we did a conversion report an error.
               if (iconv_fd != (iconv_t)-1 && conv_error == 0) {
-                conv_error = readfile_linenr(linecnt, (char_u *)ptr, p);
+                conv_error = readfile_linenr(linecnt, ptr, (char *)p);
               }
-#endif
+
               // Remember the first linenr with an illegal byte
               if (conv_error == 0 && illegal_byte == 0) {
-                illegal_byte = readfile_linenr(linecnt, (char_u *)ptr, p);
+                illegal_byte = readfile_linenr(linecnt, ptr, (char *)p);
               }
 
               // Drop, keep or replace the bad byte.
@@ -1436,17 +1413,13 @@ retry:
           // Detected a UTF-8 error.
 rewind_retry:
           // Retry reading with another conversion.
-#ifdef HAVE_ICONV
           if (*p_ccv != NUL && iconv_fd != (iconv_t)-1) {
             // iconv() failed, try 'charconvert'
             did_iconv = true;
           } else {
-#endif
-          // use next item from 'fileencodings'
-          advance_fenc = true;
-#ifdef HAVE_ICONV
-        }
-#endif
+            // use next item from 'fileencodings'
+            advance_fenc = true;
+          }
           file_rewind = true;
           goto retry;
         }
@@ -1542,7 +1515,7 @@ rewind_retry:
               break;
             }
             if (read_undo_file) {
-              sha256_update(&sha_ctx, (char_u *)line_start, (size_t)len);
+              sha256_update(&sha_ctx, (uint8_t *)line_start, (size_t)len);
             }
             lnum++;
             if (--read_count == 0) {
@@ -1598,7 +1571,7 @@ rewind_retry:
               break;
             }
             if (read_undo_file) {
-              sha256_update(&sha_ctx, (char_u *)line_start, (size_t)len);
+              sha256_update(&sha_ctx, (uint8_t *)line_start, (size_t)len);
             }
             lnum++;
             if (--read_count == 0) {
@@ -1623,16 +1596,28 @@ failed:
     error = false;
   }
 
+  // In Dos format ignore a trailing CTRL-Z, unless 'binary' is set.
+  // In old days the file length was in sector count and the CTRL-Z the
+  // marker where the file really ended.  Assuming we write it to a file
+  // system that keeps file length properly the CTRL-Z should be dropped.
+  // Set the 'endoffile' option so the user can decide what to write later.
+  // In Unix format the CTRL-Z is just another character.
+  if (linerest != 0
+      && !curbuf->b_p_bin
+      && fileformat == EOL_DOS
+      && ptr[-1] == Ctrl_Z) {
+    ptr--;
+    linerest--;
+    if (set_options) {
+      curbuf->b_p_eof = true;
+    }
+  }
+
   // If we get EOF in the middle of a line, note the fact and
   // complete the line ourselves.
-  // In Dos format ignore a trailing CTRL-Z, unless 'binary' set.
   if (!error
       && !got_int
-      && linerest != 0
-      && !(!curbuf->b_p_bin
-           && fileformat == EOL_DOS
-           && *line_start == Ctrl_Z
-           && ptr == line_start + 1)) {
+      && linerest != 0) {
     // remember for when writing
     if (set_options) {
       curbuf->b_p_eol = false;
@@ -1643,7 +1628,7 @@ failed:
       error = true;
     } else {
       if (read_undo_file) {
-        sha256_update(&sha_ctx, (char_u *)line_start, (size_t)len);
+        sha256_update(&sha_ctx, (uint8_t *)line_start, (size_t)len);
       }
       read_no_eol_lnum = ++lnum;
     }
@@ -1659,11 +1644,9 @@ failed:
   if (fenc_alloced) {
     xfree(fenc);
   }
-#ifdef HAVE_ICONV
   if (iconv_fd != (iconv_t)-1) {
     iconv_close(iconv_fd);
   }
-#endif
 
   if (!read_buffer && !read_stdin) {
     close(fd);  // errors are ignored
@@ -1734,7 +1717,7 @@ failed:
     }
 
     if (!filtering && !(flags & READ_DUMMY) && !silent) {
-      add_quoted_fname((char *)IObuff, IOSIZE, curbuf, (const char *)sfname);
+      add_quoted_fname(IObuff, IOSIZE, curbuf, (const char *)sfname);
       c = false;
 
 #ifdef UNIX
@@ -1799,7 +1782,7 @@ failed:
       msg_scrolled_ign = true;
 
       if (!read_stdin && !read_buffer) {
-        p = (char_u *)msg_trunc_attr((char *)IObuff, false, 0);
+        p = (char_u *)msg_trunc_attr(IObuff, false, 0);
       }
 
       if (read_stdin || read_buffer || restart_edit != 0
@@ -1863,7 +1846,7 @@ failed:
     char_u hash[UNDO_HASH_SIZE];
 
     sha256_finish(&sha_ctx, hash);
-    u_read_undo(NULL, hash, (char_u *)fname);
+    u_read_undo(NULL, hash, fname);
   }
 
   if (!read_stdin && !read_fifo && (!read_buffer || sfname != NULL)) {
@@ -1919,7 +1902,7 @@ failed:
 bool is_dev_fd_file(char *fname)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
 {
-  return STRNCMP(fname, "/dev/fd/", 8) == 0
+  return strncmp(fname, "/dev/fd/", 8) == 0
          && ascii_isdigit((uint8_t)fname[8])
          && *skipdigits(fname + 9) == NUL
          && (fname[9] != NUL
@@ -1934,9 +1917,9 @@ bool is_dev_fd_file(char *fname)
 /// @param linecnt  line count before reading more bytes
 /// @param p        start of more bytes read
 /// @param endp     end of more bytes read
-static linenr_T readfile_linenr(linenr_T linecnt, char_u *p, char_u *endp)
+static linenr_T readfile_linenr(linenr_T linecnt, char *p, const char *endp)
 {
-  char_u *s;
+  char *s;
   linenr_T lnum;
 
   lnum = curbuf->b_ml.ml_line_count - linecnt + 1;
@@ -1990,11 +1973,13 @@ void set_file_options(int set_options, exarg_T *eap)
 /// Set forced 'fileencoding'.
 void set_forced_fenc(exarg_T *eap)
 {
-  if (eap->force_enc != 0) {
-    char *fenc = enc_canonize(eap->cmd + eap->force_enc);
-    set_string_option_direct("fenc", -1, fenc, OPT_FREE|OPT_LOCAL, 0);
-    xfree(fenc);
+  if (eap->force_enc == 0) {
+    return;
   }
+
+  char *fenc = enc_canonize(eap->cmd + eap->force_enc);
+  set_string_option_direct("fenc", -1, fenc, OPT_FREE|OPT_LOCAL, 0);
+  xfree(fenc);
 }
 
 /// Find next fileencoding to use from 'fileencodings'.
@@ -2014,7 +1999,7 @@ static char *next_fenc(char **pp, bool *alloced)
     *pp = NULL;
     return "";
   }
-  p = vim_strchr((*pp), ',');
+  p = vim_strchr(*pp, ',');
   if (p == NULL) {
     r = enc_canonize(*pp);
     *pp += strlen(*pp);
@@ -2039,22 +2024,22 @@ static char *next_fenc(char **pp, bool *alloced)
 ///
 /// @return       name of the resulting converted file (the caller should delete it after reading it).
 ///               Returns NULL if the conversion failed ("*fdp" is not set) .
-static char_u *readfile_charconvert(char_u *fname, char_u *fenc, int *fdp)
+static char *readfile_charconvert(char *fname, char *fenc, int *fdp)
 {
-  char_u *tmpname;
+  char *tmpname;
   char *errmsg = NULL;
 
-  tmpname = (char_u *)vim_tempname();
+  tmpname = vim_tempname();
   if (tmpname == NULL) {
     errmsg = _("Can't find temp file for conversion");
   } else {
     close(*fdp);                // close the input file, ignore errors
     *fdp = -1;
-    if (eval_charconvert((char *)fenc, "utf-8",
-                         (char *)fname, (char *)tmpname) == FAIL) {
+    if (eval_charconvert(fenc, "utf-8",
+                         fname, tmpname) == FAIL) {
       errmsg = _("Conversion with 'charconvert' failed");
     }
-    if (errmsg == NULL && (*fdp = os_open((char *)tmpname, O_RDONLY, 0)) < 0) {
+    if (errmsg == NULL && (*fdp = os_open(tmpname, O_RDONLY, 0)) < 0) {
       errmsg = _("can't read output of 'charconvert'");
     }
   }
@@ -2064,14 +2049,14 @@ static char_u *readfile_charconvert(char_u *fname, char_u *fenc, int *fdp)
     // another type of conversion might still work.
     msg(errmsg);
     if (tmpname != NULL) {
-      os_remove((char *)tmpname);  // delete converted file
+      os_remove(tmpname);  // delete converted file
       XFREE_CLEAR(tmpname);
     }
   }
 
   // If the input file is closed, open it (caller should check for error).
   if (*fdp < 0) {
-    *fdp = os_open((char *)fname, O_RDONLY, 0);
+    *fdp = os_open(fname, O_RDONLY, 0);
   }
 
   return tmpname;
@@ -2191,8 +2176,7 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
     return FAIL;
   }
 
-  // Disallow writing from .exrc and .vimrc in current directory for
-  // security reasons.
+  // Disallow writing in secure mode.
   if (check_secure()) {
     return FAIL;
   }
@@ -2208,9 +2192,7 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
   write_info.bw_conv_error = false;
   write_info.bw_conv_error_lnum = 0;
   write_info.bw_restlen = 0;
-#ifdef HAVE_ICONV
   write_info.bw_iconv_fd = (iconv_t)-1;
-#endif
 
   // After writing a file changedtick changes but we don't want to display
   // the line.
@@ -2229,7 +2211,7 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
       && !filtering
       && (!append || vim_strchr(p_cpo, CPO_FNAMEAPP) != NULL)
       && vim_strchr(p_cpo, CPO_FNAMEW) != NULL) {
-    if (set_rw_fname((char_u *)fname, (char_u *)sfname) == FAIL) {
+    if (set_rw_fname(fname, sfname) == FAIL) {
       return FAIL;
     }
     buf = curbuf;           // just in case autocmds made "buf" invalid
@@ -2448,7 +2430,7 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
   if (!filtering) {
     filemess(buf,
 #ifndef UNIX
-             (char_u *)sfname,
+             sfname,
 #else
              fname,
 #endif
@@ -2492,7 +2474,7 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
   }
 #else  // win32
   // Check for a writable device name.
-  c = fname == NULL ? NODE_OTHER : os_nodetype((char *)fname);
+  c = fname == NULL ? NODE_OTHER : os_nodetype(fname);
   if (c == NODE_OTHER) {
     SET_ERRMSG_NUM("E503", _("is not a file or writable device"));
     goto fail;
@@ -2510,7 +2492,7 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
       goto fail;
     }
     if (overwriting) {
-      os_fileinfo((char *)fname, &file_info_old);
+      os_fileinfo(fname, &file_info_old);
     }
   }
 #endif  // !UNIX
@@ -2541,13 +2523,13 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
 #ifdef HAVE_ACL
   // For systems that support ACL: get the ACL from the original file.
   if (!newfile) {
-    acl = mch_get_acl((char_u *)fname);
+    acl = os_get_acl(fname);
   }
 #endif
 
   // If 'backupskip' is not empty, don't make a backup for some files.
   dobackup = (p_wb || p_bk || *p_pm != NUL);
-  if (dobackup && *p_bsk != NUL && match_file_list(p_bsk, (char_u *)sfname, (char_u *)ffname)) {
+  if (dobackup && *p_bsk != NUL && match_file_list(p_bsk, sfname, ffname)) {
     dobackup = false;
   }
 
@@ -2590,21 +2572,21 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
         // arbitrary numbers).
         STRCPY(IObuff, fname);
         for (i = 4913;; i += 123) {
-          char *tail = path_tail((char *)IObuff);
+          char *tail = path_tail(IObuff);
           size_t size = (size_t)(tail - IObuff);
           snprintf(tail, IOSIZE - size, "%d", i);
-          if (!os_fileinfo_link((char *)IObuff, &file_info)) {
+          if (!os_fileinfo_link(IObuff, &file_info)) {
             break;
           }
         }
-        fd = os_open((char *)IObuff,
+        fd = os_open(IObuff,
                      O_CREAT|O_WRONLY|O_EXCL|O_NOFOLLOW, (int)perm);
         if (fd < 0) {           // can't write in directory
           backup_copy = true;
         } else {
 #ifdef UNIX
           os_fchown(fd, (uv_uid_t)file_info_old.stat.st_uid, (uv_gid_t)file_info_old.stat.st_gid);
-          if (!os_fileinfo((char *)IObuff, &file_info)
+          if (!os_fileinfo(IObuff, &file_info)
               || file_info.stat.st_uid != file_info_old.stat.st_uid
               || file_info.stat.st_gid != file_info_old.stat.st_gid
               || (long)file_info.stat.st_mode != perm) {
@@ -2614,7 +2596,7 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
           // Close the file before removing it, on MS-Windows we
           // can't delete an open file.
           close(fd);
-          os_remove((char *)IObuff);
+          os_remove(IObuff);
         }
       }
     }
@@ -2668,16 +2650,16 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
       dirp = p_bdir;
       while (*dirp) {
         // Isolate one directory name, using an entry in 'bdir'.
-        size_t dir_len = copy_option_part(&dirp, (char *)IObuff, IOSIZE, ",");
-        p = (char *)IObuff + dir_len;
-        bool trailing_pathseps = after_pathsep((char *)IObuff, p) && p[-1] == p[-2];
+        size_t dir_len = copy_option_part(&dirp, IObuff, IOSIZE, ",");
+        p = IObuff + dir_len;
+        bool trailing_pathseps = after_pathsep(IObuff, p) && p[-1] == p[-2];
         if (trailing_pathseps) {
           IObuff[dir_len - 2] = NUL;
         }
-        if (*dirp == NUL && !os_isdir((char *)IObuff)) {
+        if (*dirp == NUL && !os_isdir(IObuff)) {
           int ret;
           char *failed_dir;
-          if ((ret = os_mkdir_recurse((char *)IObuff, 0755, &failed_dir)) != 0) {
+          if ((ret = os_mkdir_recurse(IObuff, 0755, &failed_dir)) != 0) {
             semsg(_("E303: Unable to create directory \"%s\" for backup file: %s"),
                   failed_dir, os_strerror(ret));
             xfree(failed_dir);
@@ -2685,14 +2667,14 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
         }
         if (trailing_pathseps) {
           // Ends with '//', Use Full path
-          if ((p = make_percent_swname((char *)IObuff, fname))
+          if ((p = make_percent_swname(IObuff, fname))
               != NULL) {
             backup = modname(p, backup_ext, no_prepend_dot);
             xfree(p);
           }
         }
 
-        rootname = get_file_in_dir(fname, (char *)IObuff);
+        rootname = get_file_in_dir(fname, IObuff);
         if (rootname == NULL) {
           some_error = true;                // out of memory
           goto nobackup;
@@ -2768,10 +2750,11 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
 #endif
 
           // copy the file
-          if (os_copy(fname, backup, UV_FS_COPYFILE_FICLONE)
-              != 0) {
-            SET_ERRMSG(_("E506: Can't write to backup file "
-                         "(add ! to override)"));
+          if (os_copy(fname, backup, UV_FS_COPYFILE_FICLONE) != 0) {
+            SET_ERRMSG(_("E509: Cannot create backup file (add ! to override)"));
+            XFREE_CLEAR(backup);
+            backup = NULL;
+            continue;
           }
 
 #ifdef UNIX
@@ -2780,8 +2763,9 @@ int buf_write(buf_T *buf, char *fname, char *sfname, linenr_T start, linenr_T en
                           (double)file_info_old.stat.st_mtim.tv_sec);
 #endif
 #ifdef HAVE_ACL
-          mch_set_acl((char_u *)backup, acl);
+          os_set_acl(backup, acl);
 #endif
+          SET_ERRMSG(NULL);
           break;
         }
       }
@@ -2817,16 +2801,16 @@ nobackup:
       dirp = p_bdir;
       while (*dirp) {
         // Isolate one directory name and make the backup file name.
-        size_t dir_len = copy_option_part(&dirp, (char *)IObuff, IOSIZE, ",");
-        p = (char *)IObuff + dir_len;
-        bool trailing_pathseps = after_pathsep((char *)IObuff, p) && p[-1] == p[-2];
+        size_t dir_len = copy_option_part(&dirp, IObuff, IOSIZE, ",");
+        p = IObuff + dir_len;
+        bool trailing_pathseps = after_pathsep(IObuff, p) && p[-1] == p[-2];
         if (trailing_pathseps) {
           IObuff[dir_len - 2] = NUL;
         }
-        if (*dirp == NUL && !os_isdir((char *)IObuff)) {
+        if (*dirp == NUL && !os_isdir(IObuff)) {
           int ret;
           char *failed_dir;
-          if ((ret = os_mkdir_recurse((char *)IObuff, 0755, &failed_dir)) != 0) {
+          if ((ret = os_mkdir_recurse(IObuff, 0755, &failed_dir)) != 0) {
             semsg(_("E303: Unable to create directory \"%s\" for backup file: %s"),
                   failed_dir, os_strerror(ret));
             xfree(failed_dir);
@@ -2834,7 +2818,7 @@ nobackup:
         }
         if (trailing_pathseps) {
           // path ends with '//', use full path
-          if ((p = make_percent_swname((char *)IObuff, fname))
+          if ((p = make_percent_swname(IObuff, fname))
               != NULL) {
             backup = modname(p, backup_ext, no_prepend_dot);
             xfree(p);
@@ -2842,7 +2826,7 @@ nobackup:
         }
 
         if (backup == NULL) {
-          rootname = get_file_in_dir(fname, (char *)IObuff);
+          rootname = get_file_in_dir(fname, IObuff);
           if (rootname == NULL) {
             backup = NULL;
           } else {
@@ -2953,7 +2937,7 @@ nobackup:
   // Latin1 to Unicode conversion.  This is handled in buf_write_bytes().
   // Prepare the flags for it and allocate bw_conv_buf when needed.
   if (converted) {
-    wb_flags = get_fio_flags((char_u *)fenc);
+    wb_flags = get_fio_flags(fenc);
     if (wb_flags & (FIO_UCS2 | FIO_UCS4 | FIO_UTF16 | FIO_UTF8)) {
       // Need to allocate a buffer to translate into.
       if (wb_flags & (FIO_UCS2 | FIO_UTF16 | FIO_UTF8)) {
@@ -2969,10 +2953,9 @@ nobackup:
   }
 
   if (converted && wb_flags == 0) {
-#ifdef HAVE_ICONV
     // Use iconv() conversion when conversion is needed and it's not done
     // internally.
-    write_info.bw_iconv_fd = (iconv_t)my_iconv_open((char_u *)fenc, (char_u *)"utf-8");
+    write_info.bw_iconv_fd = (iconv_t)my_iconv_open(fenc, "utf-8");
     if (write_info.bw_iconv_fd != (iconv_t)-1) {
       // We're going to use iconv(), allocate a buffer to convert in.
       write_info.bw_conv_buflen = (size_t)bufsize * ICONV_MULT;
@@ -2982,28 +2965,21 @@ nobackup:
       }
       write_info.bw_first = true;
     } else {
-#endif
-
-    // When the file needs to be converted with 'charconvert' after
-    // writing, write to a temp file instead and let the conversion
-    // overwrite the original file.
-    if (*p_ccv != NUL) {
-      wfname = vim_tempname();
-      if (wfname == NULL) {  // Can't write without a tempfile!
-        SET_ERRMSG(_("E214: Can't find temp file for writing"));
-        goto restore_backup;
+      // When the file needs to be converted with 'charconvert' after
+      // writing, write to a temp file instead and let the conversion
+      // overwrite the original file.
+      if (*p_ccv != NUL) {
+        wfname = vim_tempname();
+        if (wfname == NULL) {  // Can't write without a tempfile!
+          SET_ERRMSG(_("E214: Can't find temp file for writing"));
+          goto restore_backup;
+        }
       }
     }
   }
 
-#ifdef HAVE_ICONV
-}
-#endif
-
   if (converted && wb_flags == 0
-#ifdef HAVE_ICONV
       && write_info.bw_iconv_fd == (iconv_t)-1
-#endif
       && wfname == fname) {
     if (!forceit) {
       SET_ERRMSG(_("E213: Cannot convert (add ! to write without conversion)"));
@@ -3039,9 +3015,11 @@ nobackup:
       // false.
       while ((fd = os_open(wfname,
                            O_WRONLY |
-                           (append ?
-                            (forceit ? (O_APPEND | O_CREAT) : O_APPEND)
-                                     : (O_CREAT | O_TRUNC)),
+                           (append
+                            ? (forceit
+                               ? (O_APPEND | O_CREAT)
+                               : O_APPEND)
+                            : (O_CREAT | O_TRUNC)),
                            perm < 0 ? 0666 : (perm & 0777))) < 0) {
         // A forced write will try to create a new file if the old one
         // is still readonly. This may also happen when the directory
@@ -3122,7 +3100,7 @@ restore_backup:
     }
     SET_ERRMSG(NULL);
 
-    write_info.bw_buf = (char_u *)buffer;
+    write_info.bw_buf = buffer;
     nchars = 0;
 
     // use "++bin", "++nobin" or 'binary'
@@ -3135,7 +3113,7 @@ restore_backup:
     // Skip the BOM when appending and the file already existed, the BOM
     // only makes sense at the start of the file.
     if (buf->b_p_bomb && !write_bin && (!append || perm < 0)) {
-      write_info.bw_len = make_bom((char_u *)buffer, (char_u *)fenc);
+      write_info.bw_len = make_bom((char_u *)buffer, fenc);
       if (write_info.bw_len > 0) {
         // don't convert
         write_info.bw_flags = FIO_NOCONVERT | wb_flags;
@@ -3167,7 +3145,7 @@ restore_backup:
       // Keep it fast!
       ptr = ml_get_buf(buf, lnum, false) - 1;
       if (write_undo_file) {
-        sha256_update(&sha_ctx, (char_u *)ptr + 1, (uint32_t)(strlen(ptr + 1) + 1));
+        sha256_update(&sha_ctx, (uint8_t *)ptr + 1, (uint32_t)(strlen(ptr + 1) + 1));
       }
       while ((c = *++ptr) != NUL) {
         if (c == NL) {
@@ -3241,6 +3219,11 @@ restore_backup:
       nchars += len;
     }
 
+    if (!buf->b_p_fixeol && buf->b_p_eof) {
+      // write trailing CTRL-Z
+      (void)write_eintr(write_info.bw_fd, "\x1a", 1);
+    }
+
     // Stop when writing done or an error was encountered.
     if (!checking_conversion || end == 0) {
       break;
@@ -3308,7 +3291,7 @@ restore_backup:
     // Probably need to set the ACL before changing the user (can't set the
     // ACL on a file the user doesn't own).
     if (!backup_copy) {
-      mch_set_acl((char_u *)wfname, acl);
+      os_set_acl(wfname, acl);
     }
 #endif
 
@@ -3336,7 +3319,7 @@ restore_backup:
         } else {
           errmsg_allocated = true;
           SET_ERRMSG(xmalloc(300));
-          vim_snprintf(errmsg, 300,
+          vim_snprintf(errmsg, 300,  // NOLINT(runtime/printf)
                        _("E513: write error, conversion failed in line %" PRIdLINENR
                          " (make 'fenc' empty to override)"),
                        write_info.bw_conv_error_lnum);
@@ -3385,13 +3368,13 @@ restore_backup:
   fname = sfname;           // use shortname now, for the messages
 #endif
   if (!filtering) {
-    add_quoted_fname((char *)IObuff, IOSIZE, buf, (const char *)fname);
+    add_quoted_fname(IObuff, IOSIZE, buf, (const char *)fname);
     c = false;
     if (write_info.bw_conv_error) {
       STRCAT(IObuff, _(" CONVERSION ERROR"));
       c = true;
       if (write_info.bw_conv_error_lnum != 0) {
-        vim_snprintf_add((char *)IObuff, IOSIZE, _(" in line %" PRId64 ";"),
+        vim_snprintf_add(IObuff, IOSIZE, _(" in line %" PRId64 ";"),
                          (int64_t)write_info.bw_conv_error_lnum);
       }
     } else if (notconverted) {
@@ -3425,7 +3408,7 @@ restore_backup:
       }
     }
 
-    set_keep_msg(msg_trunc_attr((char *)IObuff, false, 0), 0);
+    set_keep_msg(msg_trunc_attr(IObuff, false, 0), 0);
   }
 
   // When written everything correctly: reset 'modified'.  Unless not
@@ -3517,22 +3500,20 @@ nofail:
   }
   xfree(fenc_tofree);
   xfree(write_info.bw_conv_buf);
-#ifdef HAVE_ICONV
   if (write_info.bw_iconv_fd != (iconv_t)-1) {
     iconv_close(write_info.bw_iconv_fd);
     write_info.bw_iconv_fd = (iconv_t)-1;
   }
-#endif
 #ifdef HAVE_ACL
-  mch_free_acl(acl);
+  os_free_acl(acl);
 #endif
 
   if (errmsg != NULL) {
     // - 100 to save some space for further error message
 #ifndef UNIX
-    add_quoted_fname((char *)IObuff, IOSIZE - 100, buf, (const char *)sfname);
+    add_quoted_fname(IObuff, IOSIZE - 100, buf, (const char *)sfname);
 #else
-    add_quoted_fname((char *)IObuff, IOSIZE - 100, buf, (const char *)fname);
+    add_quoted_fname(IObuff, IOSIZE - 100, buf, (const char *)fname);
 #endif
     if (errnum != NULL) {
       if (errmsgarg != 0) {
@@ -3571,10 +3552,10 @@ nofail:
   // When writing the whole file and 'undofile' is set, also write the undo
   // file.
   if (retval == OK && write_undo_file) {
-    char hash[UNDO_HASH_SIZE];
+    uint8_t hash[UNDO_HASH_SIZE];
 
-    sha256_finish(&sha_ctx, (char_u *)hash);
-    u_write_undo(NULL, false, buf, (char_u *)hash);
+    sha256_finish(&sha_ctx, hash);
+    u_write_undo(NULL, false, buf, hash);
   }
 
   if (!should_abort(retval)) {
@@ -3618,7 +3599,7 @@ nofail:
 
 /// Set the name of the current buffer.  Use when the buffer doesn't have a
 /// name and a ":r" or ":w" command with a file name is used.
-static int set_rw_fname(char_u *fname, char_u *sfname)
+static int set_rw_fname(char *fname, char *sfname)
 {
   buf_T *buf = curbuf;
 
@@ -3636,7 +3617,7 @@ static int set_rw_fname(char_u *fname, char_u *sfname)
     return FAIL;
   }
 
-  if (setfname(curbuf, (char *)fname, (char *)sfname, false) == OK) {
+  if (setfname(curbuf, fname, sfname, false) == OK) {
     curbuf->b_flags |= BF_NOTEDITED;
   }
 
@@ -3709,22 +3690,22 @@ static bool msg_add_fileformat(int eol_type)
 /// Append line and character count to IObuff.
 void msg_add_lines(int insert_space, long lnum, off_T nchars)
 {
-  char_u *p;
+  char *p;
 
-  p = (char_u *)IObuff + STRLEN(IObuff);
+  p = IObuff + strlen(IObuff);
 
   if (insert_space) {
     *p++ = ' ';
   }
   if (shortmess(SHM_LINES)) {
-    vim_snprintf((char *)p, (size_t)(IOSIZE - (p - (char_u *)IObuff)), "%" PRId64 "L, %" PRId64 "B",
+    vim_snprintf(p, (size_t)(IOSIZE - (p - IObuff)), "%" PRId64 "L, %" PRId64 "B",
                  (int64_t)lnum, (int64_t)nchars);
   } else {
-    vim_snprintf((char *)p, (size_t)(IOSIZE - (p - (char_u *)IObuff)),
+    vim_snprintf(p, (size_t)(IOSIZE - (p - IObuff)),
                  NGETTEXT("%" PRId64 " line, ", "%" PRId64 " lines, ", lnum),
                  (int64_t)lnum);
-    p += STRLEN(p);
-    vim_snprintf((char *)p, (size_t)(IOSIZE - (p - (char_u *)IObuff)),
+    p += strlen(p);
+    vim_snprintf(p, (size_t)(IOSIZE - (p - IObuff)),
                  NGETTEXT("%" PRId64 " byte", "%" PRId64 " bytes", nchars),
                  (int64_t)nchars);
   }
@@ -3767,7 +3748,7 @@ static bool time_differs(const FileInfo *file_info, long mtime, long mtime_ns) F
          || file_info->stat.st_mtim.tv_sec - mtime > 1
          || mtime - file_info->stat.st_mtim.tv_sec > 1;
 #else
-         || (long)file_info->stat.st_mtim.tv_sec != mtime;
+         || file_info->stat.st_mtim.tv_sec != mtime;
 #endif
 }
 
@@ -3778,7 +3759,7 @@ static bool time_differs(const FileInfo *file_info, long mtime, long mtime_ns) F
 static int buf_write_bytes(struct bw_info *ip)
 {
   int wlen;
-  char_u *buf = ip->bw_buf;        // data to write
+  char *buf = ip->bw_buf;        // data to write
   int len = ip->bw_len;                 // length of data
 #ifdef HAS_BW_FLAGS
   int flags = ip->bw_flags;             // extra flags
@@ -3786,7 +3767,7 @@ static int buf_write_bytes(struct bw_info *ip)
 
   // Skip conversion when writing the BOM.
   if (!(flags & FIO_NOCONVERT)) {
-    char_u *p;
+    char *p;
     unsigned c;
     int n;
 
@@ -3794,7 +3775,7 @@ static int buf_write_bytes(struct bw_info *ip)
       // Convert latin1 in the buffer to UTF-8 in the file.
       p = ip->bw_conv_buf;              // translate to buffer
       for (wlen = 0; wlen < len; wlen++) {
-        p += utf_char2bytes(buf[wlen], (char *)p);
+        p += utf_char2bytes((uint8_t)buf[wlen], p);
       }
       buf = ip->bw_conv_buf;
       len = (int)(p - ip->bw_conv_buf);
@@ -3818,7 +3799,7 @@ static int buf_write_bytes(struct bw_info *ip)
             l = len;
           }
           memmove(ip->bw_rest + ip->bw_restlen, buf, (size_t)l);
-          n = utf_ptr2len_len(ip->bw_rest, ip->bw_restlen + l);
+          n = utf_ptr2len_len((char *)ip->bw_rest, ip->bw_restlen + l);
           if (n > ip->bw_restlen + len) {
             // We have an incomplete byte sequence at the end to
             // be written.  We can't convert it without the
@@ -3858,9 +3839,9 @@ static int buf_write_bytes(struct bw_info *ip)
             break;
           }
           if (n > 1) {
-            c = (unsigned)utf_ptr2char((char *)buf + wlen);
+            c = (unsigned)utf_ptr2char(buf + wlen);
           } else {
-            c = buf[wlen];
+            c = (uint8_t)buf[wlen];
           }
         }
 
@@ -3880,7 +3861,6 @@ static int buf_write_bytes(struct bw_info *ip)
       }
     }
 
-#ifdef HAVE_ICONV
     if (ip->bw_iconv_fd != (iconv_t)-1) {
       const char *from;
       size_t fromlen;
@@ -3895,17 +3875,17 @@ static int buf_write_bytes(struct bw_info *ip)
         // the bytes of the current call.  Use the end of the
         // conversion buffer for this.
         fromlen = (size_t)len + (size_t)ip->bw_restlen;
-        fp = (char *)ip->bw_conv_buf + ip->bw_conv_buflen - fromlen;
+        fp = ip->bw_conv_buf + ip->bw_conv_buflen - fromlen;
         memmove(fp, ip->bw_rest, (size_t)ip->bw_restlen);
         memmove(fp + ip->bw_restlen, buf, (size_t)len);
         from = fp;
         tolen = ip->bw_conv_buflen - fromlen;
       } else {
-        from = (const char *)buf;
+        from = buf;
         fromlen = (size_t)len;
         tolen = ip->bw_conv_buflen;
       }
-      to = (char *)ip->bw_conv_buf;
+      to = ip->bw_conv_buf;
 
       if (ip->bw_first) {
         size_t save_len = tolen;
@@ -3916,7 +3896,7 @@ static int buf_write_bytes(struct bw_info *ip)
         // There is a bug in iconv() on Linux (which appears to be
         // wide-spread) which sets "to" to NULL and messes up "tolen".
         if (to == NULL) {
-          to = (char *)ip->bw_conv_buf;
+          to = ip->bw_conv_buf;
           tolen = save_len;
         }
         ip->bw_first = false;
@@ -3937,9 +3917,8 @@ static int buf_write_bytes(struct bw_info *ip)
       ip->bw_restlen = (int)fromlen;
 
       buf = ip->bw_conv_buf;
-      len = (int)((char_u *)to - ip->bw_conv_buf);
+      len = (int)(to - ip->bw_conv_buf);
     }
-#endif
   }
 
   if (ip->bw_fd < 0) {
@@ -3957,9 +3936,9 @@ static int buf_write_bytes(struct bw_info *ip)
 /// @param flags FIO_ flags that specify which encoding to use
 ///
 /// @return true for an error, false when it's OK.
-static bool ucs2bytes(unsigned c, char_u **pp, int flags) FUNC_ATTR_NONNULL_ALL
+static bool ucs2bytes(unsigned c, char **pp, int flags) FUNC_ATTR_NONNULL_ALL
 {
-  char_u *p = *pp;
+  char_u *p = (char_u *)(*pp);
   bool error = false;
   int cc;
 
@@ -4013,7 +3992,7 @@ static bool ucs2bytes(unsigned c, char_u **pp, int flags) FUNC_ATTR_NONNULL_ALL
     }
   }
 
-  *pp = p;
+  *pp = (char *)p;
   return error;
 }
 
@@ -4036,8 +4015,8 @@ static bool need_conversion(const char *fenc)
   } else {
     // Ignore difference between "ansi" and "latin1", "ucs-4" and
     // "ucs-4be", etc.
-    enc_flags = get_fio_flags((char_u *)p_enc);
-    fenc_flags = get_fio_flags((char_u *)fenc);
+    enc_flags = get_fio_flags(p_enc);
+    fenc_flags = get_fio_flags(fenc);
     same_encoding = (enc_flags != 0 && fenc_flags == enc_flags);
   }
   if (same_encoding) {
@@ -4055,12 +4034,12 @@ static bool need_conversion(const char *fenc)
 /// use 'encoding'.
 ///
 /// @param name string to check for encoding
-static int get_fio_flags(const char_u *name)
+static int get_fio_flags(const char *name)
 {
   int prop;
 
   if (*name == NUL) {
-    name = (char_u *)p_enc;
+    name = p_enc;
   }
   prop = enc_canon_props(name);
   if (prop & ENC_UNICODE) {
@@ -4096,8 +4075,9 @@ static int get_fio_flags(const char_u *name)
 ///
 /// @return  the name of the encoding and set "*lenp" to the length or,
 ///          NULL when no BOM found.
-static char_u *check_for_bom(char_u *p, long size, int *lenp, int flags)
+static char *check_for_bom(const char *p_in, long size, int *lenp, int flags)
 {
+  const uint8_t *p = (const uint8_t *)p_in;
   char *name = NULL;
   int len = 2;
 
@@ -4133,16 +4113,16 @@ static char_u *check_for_bom(char_u *p, long size, int *lenp, int flags)
   }
 
   *lenp = len;
-  return (char_u *)name;
+  return name;
 }
 
 /// Generate a BOM in "buf[4]" for encoding "name".
 ///
 /// @return  the length of the BOM (zero when no BOM).
-static int make_bom(char_u *buf, char_u *name)
+static int make_bom(char_u *buf, char *name)
 {
   int flags;
-  char_u *p;
+  char *p;
 
   flags = get_fio_flags(name);
 
@@ -4157,9 +4137,9 @@ static int make_bom(char_u *buf, char_u *name)
     buf[2] = 0xbf;
     return 3;
   }
-  p = buf;
+  p = (char *)buf;
   (void)ucs2bytes(0xfeff, &p, flags);
-  return (int)(p - buf);
+  return (int)((char_u *)p - buf);
 }
 
 /// Shorten filename of a buffer.
@@ -4171,7 +4151,7 @@ static int make_bom(char_u *buf, char_u *name)
 ///
 /// For buffers that have buftype "nofile" or "scratch": never change the file
 /// name.
-void shorten_buf_fname(buf_T *buf, char_u *dirname, int force)
+void shorten_buf_fname(buf_T *buf, char *dirname, int force)
 {
   char *p;
 
@@ -4180,11 +4160,11 @@ void shorten_buf_fname(buf_T *buf, char_u *dirname, int force)
       && !path_with_url(buf->b_fname)
       && (force
           || buf->b_sfname == NULL
-          || path_is_absolute((char_u *)buf->b_sfname))) {
+          || path_is_absolute(buf->b_sfname))) {
     if (buf->b_sfname != buf->b_ffname) {
       XFREE_CLEAR(buf->b_sfname);
     }
-    p = path_shorten_fname(buf->b_ffname, (char *)dirname);
+    p = path_shorten_fname(buf->b_ffname, dirname);
     if (p != NULL) {
       buf->b_sfname = xstrdup(p);
       buf->b_fname = buf->b_sfname;
@@ -4198,11 +4178,11 @@ void shorten_buf_fname(buf_T *buf, char_u *dirname, int force)
 /// Shorten filenames for all buffers.
 void shorten_fnames(int force)
 {
-  char_u dirname[MAXPATHL];
+  char dirname[MAXPATHL];
 
   os_dirname(dirname, MAXPATHL);
   FOR_ALL_BUFFERS(buf) {
-    shorten_buf_fname(buf, dirname, force);
+    shorten_buf_fname(buf, (char *)dirname, force);
 
     // Always make the swap file name a full path, a "nofile" buffer may
     // also have a swap file.
@@ -4247,7 +4227,7 @@ char *modname(const char *fname, const char *ext, bool prepend_dot)
   // (we need the full path in case :cd is used).
   if (fname == NULL || *fname == NUL) {
     retval = xmalloc(MAXPATHL + extlen + 3);  // +3 for PATHSEP, "_" (Win), NUL
-    if (os_dirname((char_u *)retval, MAXPATHL) == FAIL
+    if (os_dirname(retval, MAXPATHL) == FAIL
         || strlen(retval) == 0) {
       xfree(retval);
       return NULL;
@@ -4258,7 +4238,7 @@ char *modname(const char *fname, const char *ext, bool prepend_dot)
   } else {
     fnamelen = strlen(fname);
     retval = xmalloc(fnamelen + extlen + 3);
-    strcpy(retval, fname);
+    strcpy(retval, fname);  // NOLINT(runtime/printf)
   }
 
   // Search backwards until we hit a '/', '\' or ':'.
@@ -4276,12 +4256,11 @@ char *modname(const char *fname, const char *ext, bool prepend_dot)
     ptr[BASENAMELEN] = '\0';
   }
 
-  char *s;
-  s = ptr + strlen(ptr);
+  char *s = ptr + strlen(ptr);
 
   // Append the extension.
   // ext can start with '.' and cannot exceed 3 more characters.
-  strcpy(s, ext);
+  strcpy(s, ext);  // NOLINT(runtime/printf)
 
   char *e;
   // Prepend the dot if needed.
@@ -4315,7 +4294,8 @@ char *modname(const char *fname, const char *ext, bool prepend_dot)
 /// @param fp file to read from
 ///
 /// @return true for EOF or error
-bool vim_fgets(char_u *buf, int size, FILE *fp) FUNC_ATTR_NONNULL_ALL
+bool vim_fgets(char *buf, int size, FILE *fp)
+  FUNC_ATTR_NONNULL_ALL
 {
   char *retval;
 
@@ -4324,7 +4304,7 @@ bool vim_fgets(char_u *buf, int size, FILE *fp) FUNC_ATTR_NONNULL_ALL
 
   do {
     errno = 0;
-    retval = fgets((char *)buf, size, fp);
+    retval = fgets(buf, size, fp);
   } while (retval == NULL && errno == EINTR && ferror(fp));
 
   if (buf[size - 2] != NUL && buf[size - 2] != '\n') {
@@ -4518,7 +4498,7 @@ int vim_rename(const char *from, const char *to)
   }
 
   if (use_tmp_file) {
-    char_u tempname[MAXPATHL + 1];
+    char tempname[MAXPATHL + 1];
 
     // Find a name that doesn't exist and is in the same directory.
     // Rename "from" to "tempname" and then rename "tempname" to "to".
@@ -4527,17 +4507,17 @@ int vim_rename(const char *from, const char *to)
     }
     STRCPY(tempname, from);
     for (n = 123; n < 99999; n++) {
-      char *tail = path_tail((char *)tempname);
-      snprintf(tail, (size_t)((MAXPATHL + 1) - (tail - (char *)tempname - 1)), "%d", n);
+      char *tail = path_tail(tempname);
+      snprintf(tail, (size_t)((MAXPATHL + 1) - (tail - tempname - 1)), "%d", n);
 
-      if (!os_path_exists((char *)tempname)) {
-        if (os_rename((char_u *)from, tempname) == OK) {
-          if (os_rename(tempname, (char_u *)to) == OK) {
+      if (!os_path_exists(tempname)) {
+        if (os_rename(from, tempname) == OK) {
+          if (os_rename(tempname, to) == OK) {
             return 0;
           }
           // Strange, the second step failed.  Try moving the
           // file back and return failure.
-          (void)os_rename(tempname, (char_u *)from);
+          (void)os_rename(tempname, from);
           return -1;
         }
         // If it fails for one temp name it will most likely fail
@@ -4555,7 +4535,7 @@ int vim_rename(const char *from, const char *to)
   os_remove((char *)to);
 
   // First try a normal rename, return if it works.
-  if (os_rename((char_u *)from, (char_u *)to) == OK) {
+  if (os_rename(from, to) == OK) {
     return 0;
   }
 
@@ -4563,12 +4543,12 @@ int vim_rename(const char *from, const char *to)
   perm = os_getperm(from);
 #ifdef HAVE_ACL
   // For systems that support ACL: get the ACL from the original file.
-  acl = mch_get_acl((char_u *)from);
+  acl = os_get_acl(from);
 #endif
   fd_in = os_open((char *)from, O_RDONLY, 0);
   if (fd_in < 0) {
 #ifdef HAVE_ACL
-    mch_free_acl(acl);
+    os_free_acl(acl);
 #endif
     return -1;
   }
@@ -4579,7 +4559,7 @@ int vim_rename(const char *from, const char *to)
   if (fd_out < 0) {
     close(fd_in);
 #ifdef HAVE_ACL
-    mch_free_acl(acl);
+    os_free_acl(acl);
 #endif
     return -1;
   }
@@ -4591,7 +4571,7 @@ int vim_rename(const char *from, const char *to)
     close(fd_out);
     close(fd_in);
 #ifdef HAVE_ACL
-    mch_free_acl(acl);
+    os_free_acl(acl);
 #endif
     return -1;
   }
@@ -4613,11 +4593,11 @@ int vim_rename(const char *from, const char *to)
     to = from;
   }
 #ifndef UNIX  // For Unix os_open() already set the permission.
-  os_setperm((const char *)to, perm);
+  os_setperm(to, perm);
 #endif
 #ifdef HAVE_ACL
-  mch_set_acl((char_u *)to, acl);
-  mch_free_acl(acl);
+  os_set_acl(to, acl);
+  os_free_acl(acl);
 #endif
   if (errmsg != NULL) {
     semsg(errmsg, to);
@@ -4924,7 +4904,7 @@ int buf_check_timestamp(buf_T *buf)
         }
         msg_clr_eos();
         (void)msg_end();
-        if (emsg_silent == 0) {
+        if (emsg_silent == 0 && !in_assert_fails) {
           ui_flush();
           // give the user some time to think about it
           os_delay(1004L, true);
@@ -4975,7 +4955,7 @@ void buf_reload(buf_T *buf, int orig_mode, bool reload_options)
   aco_save_T aco;
   int flags = READ_NEW;
 
-  // set curwin/curbuf for "buf" and save some things
+  // Set curwin/curbuf for "buf" and save some things.
   aucmd_prepbuf(&aco, buf);
 
   // Unless reload_options is set, we only want to read the text from the
@@ -5122,11 +5102,11 @@ void write_lnum_adjust(linenr_T offset)
 #if defined(BACKSLASH_IN_FILENAME)
 /// Convert all backslashes in fname to forward slashes in-place,
 /// unless when it looks like a URL.
-void forward_slash(char_u *fname)
+void forward_slash(char *fname)
 {
-  char_u *p;
+  char *p;
 
-  if (path_with_url((const char *)fname)) {
+  if (path_with_url(fname)) {
     return;
   }
   for (p = fname; *p != NUL; p++) {
@@ -5139,6 +5119,9 @@ void forward_slash(char_u *fname)
 
 /// Path to Nvim's own temp dir. Ends in a slash.
 static char *vim_tempdir = NULL;
+#if defined(HAVE_FLOCK) && defined(HAVE_DIRFD)
+DIR *vim_tempdir_dp = NULL;  ///< File descriptor of temp dir
+#endif
 
 /// Creates a directory for private use by this instance of Nvim, trying each of
 /// `TEMP_DIR_NAMES` until one succeeds.
@@ -5211,10 +5194,9 @@ static void vim_mktempdir(void)
     if (vim_settempdir(path)) {
       // Successfully created and set temporary directory so stop trying.
       break;
-    } else {
-      // Couldn't set `vim_tempdir` to `path` so remove created directory.
-      os_rmdir(path);
     }
+    // Couldn't set `vim_tempdir` to `path` so remove created directory.
+    os_rmdir(path);
   }
   (void)umask(umask_save);
 }
@@ -5281,7 +5263,7 @@ int delete_recursive(const char *name)
     garray_T ga;
     if (readdir_core(&ga, exp, NULL, NULL) == OK) {
       for (int i = 0; i < ga.ga_len; i++) {
-        vim_snprintf((char *)NameBuff, MAXPATHL, "%s/%s", exp, ((char_u **)ga.ga_data)[i]);
+        vim_snprintf(NameBuff, MAXPATHL, "%s/%s", exp, ((char **)ga.ga_data)[i]);
         if (delete_recursive((const char *)NameBuff) != 0) {
           // Remember the failure but continue deleting any further
           // entries.
@@ -5304,15 +5286,50 @@ int delete_recursive(const char *name)
   return result;
 }
 
+#if defined(HAVE_FLOCK) && defined(HAVE_DIRFD)
+/// Open temporary directory and take file lock to prevent
+/// to be auto-cleaned.
+static void vim_opentempdir(void)
+{
+  if (vim_tempdir_dp != NULL) {
+    return;
+  }
+
+  DIR *dp = opendir(vim_tempdir);
+  if (dp == NULL) {
+    return;
+  }
+
+  vim_tempdir_dp = dp;
+  flock(dirfd(vim_tempdir_dp), LOCK_SH);
+}
+
+/// Close temporary directory - it automatically release file lock.
+static void vim_closetempdir(void)
+{
+  if (vim_tempdir_dp == NULL) {
+    return;
+  }
+
+  closedir(vim_tempdir_dp);
+  vim_tempdir_dp = NULL;
+}
+#endif
+
 /// Delete the temp directory and all files it contains.
 void vim_deltempdir(void)
 {
-  if (vim_tempdir != NULL) {
-    // remove the trailing path separator
-    path_tail(vim_tempdir)[-1] = NUL;
-    delete_recursive(vim_tempdir);
-    XFREE_CLEAR(vim_tempdir);
+  if (vim_tempdir == NULL) {
+    return;
   }
+
+#if defined(HAVE_FLOCK) && defined(HAVE_DIRFD)
+  vim_closetempdir();
+#endif
+  // remove the trailing path separator
+  path_tail(vim_tempdir)[-1] = NUL;
+  delete_recursive(vim_tempdir);
+  XFREE_CLEAR(vim_tempdir);
 }
 
 /// Gets path to Nvim's own temp dir (ending with slash).
@@ -5337,12 +5354,16 @@ char *vim_gettempdir(void)
 static bool vim_settempdir(char *tempdir)
 {
   char *buf = verbose_try_malloc(MAXPATHL + 2);
-  if (!buf) {
+  if (buf == NULL) {
     return false;
   }
+
   vim_FullName(tempdir, buf, MAXPATHL, false);
   add_pathsep(buf);
   vim_tempdir = xstrdup(buf);
+#if defined(HAVE_FLOCK) && defined(HAVE_DIRFD)
+  vim_opentempdir();
+#endif
   xfree(buf);
   return true;
 }
@@ -5430,28 +5451,27 @@ bool match_file_pat(char *pattern, regprog_T **prog, char *fname, char *sfname,
 /// @param ffname full file name
 ///
 /// @return true if there was a match
-bool match_file_list(char_u *list, char_u *sfname, char_u *ffname)
+bool match_file_list(char *list, char *sfname, char *ffname)
   FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ARG(1, 3)
 {
-  char_u buf[100];
-  char_u *tail;
-  char_u *regpat;
+  char buf[100];
+  char *tail;
+  char *regpat;
   char allow_dirs;
   bool match;
   char *p;
 
-  tail = (char_u *)path_tail((char *)sfname);
+  tail = path_tail(sfname);
 
   // try all patterns in 'wildignore'
-  p = (char *)list;
+  p = list;
   while (*p) {
-    copy_option_part(&p, (char *)buf, ARRAY_SIZE(buf), ",");
-    regpat = (char_u *)file_pat_to_reg_pat((char *)buf, NULL, &allow_dirs, false);
+    copy_option_part(&p, buf, ARRAY_SIZE(buf), ",");
+    regpat = file_pat_to_reg_pat(buf, NULL, &allow_dirs, false);
     if (regpat == NULL) {
       break;
     }
-    match = match_file_pat((char *)regpat, NULL, (char *)ffname, (char *)sfname, (char *)tail,
-                           (int)allow_dirs);
+    match = match_file_pat(regpat, NULL, ffname, sfname, tail, (int)allow_dirs);
     xfree(regpat);
     if (match) {
       return true;
@@ -5560,7 +5580,7 @@ char *file_pat_to_reg_pat(const char *pat, const char *pat_end, char *allow_dirs
         // "\*" to "\\.*" e.g., "dir\*.c"
         // "\?" to "\\."  e.g., "dir\??.c"
         // "\+" to "\+"   e.g., "fileX\+.c"
-        if ((vim_isfilec(p[1]) || p[1] == '*' || p[1] == '?')
+        if ((vim_isfilec((uint8_t)p[1]) || p[1] == '*' || p[1] == '?')
             && p[1] != '+') {
           reg_pat[i++] = '[';
           reg_pat[i++] = '\\';