vim-patch:9.0.1400: find_file_in_path() is not reentrant (#23146)

Problem:    find_file_in_path() is not reentrant.
Solution:   Instead of global variables pass pointers to the functions.
            (closes vim/vim#12093)

5145c9a829

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/eval/funcs.c

@@ -2146,6 +2146,9 @@ static void findfilendir(typval_T *argvars, typval_T *rettv, int find_what)
   }
 
   if (*fname != NUL && !error) {
+    char *file_to_find = NULL;
+    char *search_ctx = NULL;
+
     do {
       if (rettv->v_type == VAR_STRING || rettv->v_type == VAR_LIST) {
         xfree(fresult);
@@ -2156,13 +2159,17 @@ static void findfilendir(typval_T *argvars, typval_T *rettv, int find_what)
                                          find_what, curbuf->b_ffname,
                                          (find_what == FINDFILE_DIR
                                           ? ""
-                                          : curbuf->b_p_sua));
+                                          : curbuf->b_p_sua),
+                                         &file_to_find, &search_ctx);
       first = false;
 
       if (fresult != NULL && rettv->v_type == VAR_LIST) {
         tv_list_append_string(rettv->vval.v_list, fresult, -1);
       }
     } while ((rettv->v_type == VAR_LIST || --count > 0) && fresult != NULL);
+
+    xfree(file_to_find);
+    vim_findfile_cleanup(search_ctx);
   }
 
   if (rettv->v_type == VAR_STRING) {

src/nvim/ex_docmd.c

@@ -4976,8 +4976,13 @@ void ex_splitview(exarg_T *eap)
   }
 
   if (eap->cmdidx == CMD_sfind || eap->cmdidx == CMD_tabfind) {
+    char *file_to_find = NULL;
+    char *search_ctx = NULL;
     fname = find_file_in_path(eap->arg, strlen(eap->arg),
-                              FNAME_MESS, true, curbuf->b_ffname);
+                              FNAME_MESS, true, curbuf->b_ffname,
+                              &file_to_find, &search_ctx);
+    xfree(file_to_find);
+    vim_findfile_cleanup(search_ctx);
     if (fname == NULL) {
       goto theend;
     }
@@ -5169,17 +5174,23 @@ static void ex_resize(exarg_T *eap)
 /// ":find [+command] <file>" command.
 static void ex_find(exarg_T *eap)
 {
+  char *file_to_find = NULL;
+  char *search_ctx = NULL;
   char *fname = find_file_in_path(eap->arg, strlen(eap->arg),
-                                  FNAME_MESS, true, curbuf->b_ffname);
+                                  FNAME_MESS, true, curbuf->b_ffname,
+                                  &file_to_find, &search_ctx);
   if (eap->addr_count > 0) {
-    // Repeat finding the file "count" times.  This matters when it
+    // Repeat finding the file "count" times.  This matters when it appears
-    // appears several times in the path.
+    // several times in the path.
     linenr_T count = eap->line2;
     while (fname != NULL && --count > 0) {
       xfree(fname);
-      fname = find_file_in_path(NULL, 0, FNAME_MESS, false, curbuf->b_ffname);
+      fname = find_file_in_path(NULL, 0, FNAME_MESS, false, curbuf->b_ffname,
+                                &file_to_find, &search_ctx);
     }
   }
+  xfree(file_to_find);
+  vim_findfile_cleanup(search_ctx);
 
   if (fname == NULL) {
     return;
@@ -5211,18 +5222,17 @@ void do_exedit(exarg_T *eap, win_T *old_curwin)
     if (*eap->arg == NUL) {
       // Special case:  ":global/pat/visual\NLvi-commands"
       if (global_busy) {
-        int rd = RedrawingDisabled;
-        int nwr = no_wait_return;
-        int ms = msg_scroll;
-
         if (eap->nextcmd != NULL) {
           stuffReadbuff(eap->nextcmd);
           eap->nextcmd = NULL;
         }
 
+        const int save_rd = RedrawingDisabled;
         RedrawingDisabled = 0;
+        const int save_nwr = no_wait_return;
         no_wait_return = 0;
         need_wait_return = false;
+        const int save_ms = msg_scroll;
         msg_scroll = 0;
         redraw_all_later(UPD_NOT_VALID);
         pending_exmode_active = true;
@@ -5230,9 +5240,9 @@ void do_exedit(exarg_T *eap, win_T *old_curwin)
         normal_enter(false, true);
 
         pending_exmode_active = false;
-        RedrawingDisabled = rd;
+        RedrawingDisabled = save_rd;
-        no_wait_return = nwr;
+        no_wait_return = save_nwr;
-        msg_scroll = ms;
+        msg_scroll = save_ms;
       }
       return;
     }

src/nvim/file_search.c

@@ -1281,28 +1281,26 @@ static int ff_path_in_stoplist(char *path, int path_len, char **stopdirs_v)
 /// @param len  length of file name
 /// @param first  use count'th matching file name
 /// @param rel_fname  file name searching relative to
+/// @param[in,out] file_to_find  modified copy of file name
+/// @param[in,out] search_ctx  state of the search
 ///
 /// @return  an allocated string for the file name.  NULL for error.
-char *find_file_in_path(char *ptr, size_t len, int options, int first, char *rel_fname)
+char *find_file_in_path(char *ptr, size_t len, int options, int first, char *rel_fname,
+                        char **file_to_find, char **search_ctx)
 {
   return find_file_in_path_option(ptr, len, options, first,
                                   (*curbuf->b_p_path == NUL
                                    ? p_path
                                    : curbuf->b_p_path),
-                                  FINDFILE_BOTH, rel_fname, curbuf->b_p_sua);
+                                  FINDFILE_BOTH, rel_fname, curbuf->b_p_sua,
+                                  file_to_find, search_ctx);
 }
 
-static char *ff_file_to_find = NULL;
-static void *fdip_search_ctx = NULL;
-
 #if defined(EXITFREE)
 void free_findfile(void)
 {
-  xfree(ff_file_to_find);
+  XFREE_CLEAR(ff_expand_buffer);
-  vim_findfile_cleanup(fdip_search_ctx);
-  xfree(ff_expand_buffer);
 }
-
 #endif
 
 /// Find the directory name "ptr[len]" in the path.
@@ -1316,12 +1314,16 @@ void free_findfile(void)
 /// @param ptr  file name
 /// @param len  length of file name
 /// @param rel_fname  file name searching relative to
+/// @param[in,out] file_to_find  modified copy of file name
+/// @param[in,out] search_ctx  state of the search
 ///
 /// @return  an allocated string for the file name.  NULL for error.
-char *find_directory_in_path(char *ptr, size_t len, int options, char *rel_fname)
+char *find_directory_in_path(char *ptr, size_t len, int options, char *rel_fname,
+                             char **file_to_find, char **search_ctx)
 {
   return find_file_in_path_option(ptr, len, options, true, p_cdpath,
-                                  FINDFILE_DIR, rel_fname, "");
+                                  FINDFILE_DIR, rel_fname, "",
+                                  file_to_find, search_ctx);
 }
 
 /// @param ptr  file name
@@ -1331,9 +1333,13 @@ char *find_directory_in_path(char *ptr, size_t len, int options, char *rel_fname
 /// @param find_what  FINDFILE_FILE, _DIR or _BOTH
 /// @param rel_fname  file name we are looking relative to.
 /// @param suffixes  list of suffixes, 'suffixesadd' option
+/// @param[in,out] file_to_find  modified copy of file name
+/// @param[in,out] search_ctx_arg  state of the search
 char *find_file_in_path_option(char *ptr, size_t len, int options, int first, char *path_option,
-                               int find_what, char *rel_fname, char *suffixes)
+                               int find_what, char *rel_fname, char *suffixes, char **file_to_find,
+                               char **search_ctx_arg)
 {
+  ff_search_ctx_T **search_ctx = (ff_search_ctx_T **)search_ctx_arg;
   static char *dir;
   static int did_findfile_init = false;
   char save_char;
@@ -1357,11 +1363,11 @@ char *find_file_in_path_option(char *ptr, size_t len, int options, int first, ch
     expand_env_esc(ptr, NameBuff, MAXPATHL, false, true, NULL);
     ptr[len] = save_char;
 
-    xfree(ff_file_to_find);
+    xfree(*file_to_find);
-    ff_file_to_find = xstrdup(NameBuff);
+    *file_to_find = xstrdup(NameBuff);
     if (options & FNAME_UNESC) {
       // Change all "\ " to " ".
-      for (ptr = ff_file_to_find; *ptr != NUL; ptr++) {
+      for (ptr = *file_to_find; *ptr != NUL; ptr++) {
         if (ptr[0] == '\\' && ptr[1] == ' ') {
           memmove(ptr, ptr + 1, strlen(ptr));
         }
@@ -1369,45 +1375,45 @@ char *find_file_in_path_option(char *ptr, size_t len, int options, int first, ch
     }
   }
 
-  rel_to_curdir = (ff_file_to_find[0] == '.'
+  rel_to_curdir = ((*file_to_find)[0] == '.'
-                   && (ff_file_to_find[1] == NUL
+                   && ((*file_to_find)[1] == NUL
-                       || vim_ispathsep(ff_file_to_find[1])
+                       || vim_ispathsep((*file_to_find)[1])
-                       || (ff_file_to_find[1] == '.'
+                       || ((*file_to_find)[1] == '.'
-                           && (ff_file_to_find[2] == NUL
+                           && ((*file_to_find)[2] == NUL
-                               || vim_ispathsep(ff_file_to_find[2])))));
+                               || vim_ispathsep((*file_to_find)[2])))));
-  if (vim_isAbsName(ff_file_to_find)
+  if (vim_isAbsName(*file_to_find)
       // "..", "../path", "." and "./path": don't use the path_option
       || rel_to_curdir
 #if defined(MSWIN)
       // handle "\tmp" as absolute path
-      || vim_ispathsep(ff_file_to_find[0])
+      || vim_ispathsep((*file_to_find)[0])
       // handle "c:name" as absolute path
-      || (ff_file_to_find[0] != NUL && ff_file_to_find[1] == ':')
+      || ((*file_to_find)[0] != NUL && (*file_to_find)[1] == ':')
 #endif
       ) {
     // Absolute path, no need to use "path_option".
     // If this is not a first call, return NULL.  We already returned a
     // filename on the first call.
     if (first == true) {
-      if (path_with_url(ff_file_to_find)) {
+      if (path_with_url(*file_to_find)) {
-        file_name = xstrdup(ff_file_to_find);
+        file_name = xstrdup(*file_to_find);
         goto theend;
       }
 
       // When FNAME_REL flag given first use the directory of the file.
       // Otherwise or when this fails use the current directory.
       for (int run = 1; run <= 2; run++) {
-        size_t l = strlen(ff_file_to_find);
+        size_t l = strlen(*file_to_find);
         if (run == 1
             && rel_to_curdir
             && (options & FNAME_REL)
             && rel_fname != NULL
             && strlen(rel_fname) + l < MAXPATHL) {
           STRCPY(NameBuff, rel_fname);
-          STRCPY(path_tail(NameBuff), ff_file_to_find);
+          STRCPY(path_tail(NameBuff), *file_to_find);
           l = strlen(NameBuff);
         } else {
-          STRCPY(NameBuff, ff_file_to_find);
+          STRCPY(NameBuff, *file_to_find);
           run = 2;
         }
 
@@ -1435,14 +1441,14 @@ char *find_file_in_path_option(char *ptr, size_t len, int options, int first, ch
     // Otherwise continue to find the next match.
     if (first == true) {
       // vim_findfile_free_visited can handle a possible NULL pointer
-      vim_findfile_free_visited(fdip_search_ctx);
+      vim_findfile_free_visited(*search_ctx);
       dir = path_option;
       did_findfile_init = false;
     }
 
     for (;;) {
       if (did_findfile_init) {
-        file_name = vim_findfile(fdip_search_ctx);
+        file_name = vim_findfile(*search_ctx);
         if (file_name != NULL) {
           break;
         }
@@ -1453,8 +1459,8 @@ char *find_file_in_path_option(char *ptr, size_t len, int options, int first, ch
 
         if (dir == NULL || *dir == NUL) {
           // We searched all paths of the option, now we can free the search context.
-          vim_findfile_cleanup(fdip_search_ctx);
+          vim_findfile_cleanup(*search_ctx);
-          fdip_search_ctx = NULL;
+          *search_ctx = NULL;
           break;
         }
 
@@ -1466,10 +1472,10 @@ char *find_file_in_path_option(char *ptr, size_t len, int options, int first, ch
 
         // get the stopdir string
         r_ptr = vim_findfile_stopdir(buf);
-        fdip_search_ctx = vim_findfile_init(buf, ff_file_to_find,
+        *search_ctx = vim_findfile_init(buf, *file_to_find,
                                         r_ptr, 100, false, find_what,
-                                            fdip_search_ctx, false, rel_fname);
+                                        *search_ctx, false, rel_fname);
-        if (fdip_search_ctx != NULL) {
+        if (*search_ctx != NULL) {
           did_findfile_init = true;
         }
         xfree(buf);
@@ -1479,19 +1485,15 @@ char *find_file_in_path_option(char *ptr, size_t len, int options, int first, ch
   if (file_name == NULL && (options & FNAME_MESS)) {
     if (first == true) {
       if (find_what == FINDFILE_DIR) {
-        semsg(_("E344: Can't find directory \"%s\" in cdpath"),
+        semsg(_("E344: Can't find directory \"%s\" in cdpath"), *file_to_find);
-              ff_file_to_find);
       } else {
-        semsg(_("E345: Can't find file \"%s\" in path"),
+        semsg(_("E345: Can't find file \"%s\" in path"), *file_to_find);
-              ff_file_to_find);
       }
     } else {
       if (find_what == FINDFILE_DIR) {
-        semsg(_("E346: No more directory \"%s\" found in cdpath"),
+        semsg(_("E346: No more directory \"%s\" found in cdpath"), *file_to_find);
-              ff_file_to_find);
       } else {
-        semsg(_("E347: No more file \"%s\" found in path"),
+        semsg(_("E347: No more file \"%s\" found in path"), *file_to_find);
-              ff_file_to_find);
       }
     }
   }
@@ -1606,8 +1608,12 @@ int vim_chdirfile(char *fname, CdCause cause)
 /// Change directory to "new_dir". Search 'cdpath' for relative directory names.
 int vim_chdir(char *new_dir)
 {
-  char *dir_name = find_directory_in_path(new_dir, strlen(new_dir),
+  char *file_to_find = NULL;
-                                          FNAME_MESS, curbuf->b_ffname);
+  char *search_ctx = NULL;
+  char *dir_name = find_directory_in_path(new_dir, strlen(new_dir), FNAME_MESS,
+                                          curbuf->b_ffname, &file_to_find, &search_ctx);
+  xfree(file_to_find);
+  vim_findfile_cleanup(search_ctx);
   if (dir_name == NULL) {
     return -1;
   }

src/nvim/path.c

@@ -1690,8 +1690,11 @@ char *find_file_name_in_path(char *ptr, size_t len, int options, long count, cha
   }
 
   if (options & FNAME_EXP) {
-    file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS, true,
+    char *file_to_find = NULL;
-                                  rel_fname);
+    char *search_ctx = NULL;
+
+    file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
+                                  true, rel_fname, &file_to_find, &search_ctx);
 
     // If the file could not be found in a normal way, try applying
     // 'includeexpr' (unless done already).
@@ -1702,7 +1705,7 @@ char *find_file_name_in_path(char *ptr, size_t len, int options, long count, cha
         ptr = tofree;
         len = strlen(ptr);
         file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
-                                      true, rel_fname);
+                                      true, rel_fname, &file_to_find, &search_ctx);
       }
     }
     if (file_name == NULL && (options & FNAME_MESS)) {
@@ -1716,9 +1719,12 @@ char *find_file_name_in_path(char *ptr, size_t len, int options, long count, cha
     // appears several times in the path.
     while (file_name != NULL && --count > 0) {
       xfree(file_name);
-      file_name =
+      file_name = find_file_in_path(ptr, len, options, false, rel_fname,
-        find_file_in_path(ptr, len, options, false, rel_fname);
+                                    &file_to_find, &search_ctx);
     }
+
+    xfree(file_to_find);
+    vim_findfile_cleanup(search_ctx);
   } else {
     file_name = xstrnsave(ptr, len);
   }