Remove more OOM error handling code

From the functions:

 - ExpandBufnames
 - buf_modname()
 - do_autocmd_event()
 - ff_create_stack_element()
 - ff_get_visited_list()
 - ins_complete()
 - msg_show_console_dialog()
 - prt_find_resource()
 - vim_findfile_init()

TODO: refactor msg_show_console_dialog() to make sure it doesn't ever return
NULL.

src/buffer.c

@@ -1877,12 +1877,6 @@ int ExpandBufnames(char_u *pat, int *num_file, char_u ***file, int options)
         break;
       if (round == 1) {
         *file = (char_u **)alloc((unsigned)(count * sizeof(char_u *)));
-        if (*file == NULL) {
-          vim_regfree(prog);
-          if (patc != pat)
-            vim_free(patc);
-          return FAIL;
-        }
       }
     }
     vim_regfree(prog);

src/diff.c

@@ -1403,7 +1403,6 @@ static void diff_read(int idx_orig, int idx_new, char_u *fname)
     notset = TRUE;
   }
 
-done:
   fclose(fd);
 }
 

src/edit.c

@@ -4345,8 +4345,6 @@ static int ins_complete(int c)
         /* we need up to 2 extra chars for the prefix */
         compl_pattern = alloc(quote_meta(NULL, line + compl_col,
                 compl_length) + 2);
-        if (compl_pattern == NULL)
-          return FAIL;
         if (!vim_iswordp(line + compl_col)
             || (compl_col > 0
                 && (
@@ -4392,16 +4390,12 @@ static int ins_complete(int c)
            * alloc(7) is enough  -- Acevedo
            */
           compl_pattern = alloc(7);
-          if (compl_pattern == NULL)
-            return FAIL;
           STRCPY((char *)compl_pattern, "\\<");
           (void)quote_meta(compl_pattern + 2, line + compl_col, 1);
           STRCAT((char *)compl_pattern, "\\k");
         } else {
           compl_pattern = alloc(quote_meta(NULL, line + compl_col,
                   compl_length) + 2);
-          if (compl_pattern == NULL)
-            return FAIL;
           STRCPY((char *)compl_pattern, "\\<");
           (void)quote_meta(compl_pattern + 2, line + compl_col,
               compl_length);

src/file_search.c

@@ -280,8 +280,6 @@ vim_findfile_init (
     search_ctx = search_ctx_arg;
   else {
     search_ctx = (ff_search_ctx_T*)alloc((unsigned)sizeof(ff_search_ctx_T));
-    if (search_ctx == NULL)
-      goto error_return;
     memset(search_ctx, 0, sizeof(ff_search_ctx_T));
   }
   search_ctx->ffsc_find_what = find_what;
@@ -309,8 +307,6 @@ vim_findfile_init (
 
   if (ff_expand_buffer == NULL) {
     ff_expand_buffer = (char_u*)alloc(MAXPATHL);
-    if (ff_expand_buffer == NULL)
-      goto error_return;
   }
 
   /* Store information on starting dir now if path is relative.
@@ -382,32 +378,30 @@ vim_findfile_init (
     search_ctx->ffsc_stopdirs_v =
       (char_u **)alloc((unsigned)sizeof(char_u *));
 
-    if (search_ctx->ffsc_stopdirs_v != NULL) {
-      do {
-        char_u  *helper;
-        void    *ptr;
+    do {
+      char_u  *helper;
+      void    *ptr;
 
-        helper = walker;
-        ptr = xrealloc(search_ctx->ffsc_stopdirs_v,
-            (dircount + 1) * sizeof(char_u *));
-        search_ctx->ffsc_stopdirs_v = ptr;
-        walker = vim_strchr(walker, ';');
-        if (walker) {
-          search_ctx->ffsc_stopdirs_v[dircount-1] =
-            vim_strnsave(helper, (int)(walker - helper));
-          walker++;
-        } else
-          /* this might be "", which means ascent till top
-           * of directory tree.
-           */
-          search_ctx->ffsc_stopdirs_v[dircount-1] =
-            vim_strsave(helper);
+      helper = walker;
+      ptr = xrealloc(search_ctx->ffsc_stopdirs_v,
+          (dircount + 1) * sizeof(char_u *));
+      search_ctx->ffsc_stopdirs_v = ptr;
+      walker = vim_strchr(walker, ';');
+      if (walker) {
+        search_ctx->ffsc_stopdirs_v[dircount-1] =
+          vim_strnsave(helper, (int)(walker - helper));
+        walker++;
+      } else
+        /* this might be "", which means ascent till top
+         * of directory tree.
+         */
+        search_ctx->ffsc_stopdirs_v[dircount-1] =
+          vim_strsave(helper);
 
-        dircount++;
+      dircount++;
 
-      } while (walker != NULL);
-      search_ctx->ffsc_stopdirs_v[dircount-1] = NULL;
-    }
+    } while (walker != NULL);
+    search_ctx->ffsc_stopdirs_v[dircount-1] = NULL;
   }
 
   search_ctx->ffsc_level = level;
@@ -1074,8 +1068,6 @@ static ff_visited_list_hdr_T *ff_get_visited_list(char_u *filename, ff_visited_l
    * if we reach this we didn't find a list and we have to allocate new list
    */
   retptr = (ff_visited_list_hdr_T*)alloc((unsigned)sizeof(*retptr));
-  if (retptr == NULL)
-    return NULL;
 
   retptr->ffvl_visited_list = NULL;
   retptr->ffvl_filename = vim_strsave(filename);
@@ -1212,8 +1204,6 @@ static ff_stack_T *ff_create_stack_element(char_u *fix_part, char_u *wc_part, in
   ff_stack_T  *new;
 
   new = (ff_stack_T *)alloc((unsigned)sizeof(ff_stack_T));
-  if (new == NULL)
-    return NULL;
 
   new->ffs_prev          = NULL;
   new->ffs_filearray     = NULL;

src/fileio.c

@@ -4739,8 +4739,6 @@ buf_modname (
    */
   if (fname == NULL || *fname == NUL) {
     retval = alloc((unsigned)(MAXPATHL + extlen + 3));
-    if (retval == NULL)
-      return NULL;
     if (os_dirname(retval, MAXPATHL) == FAIL ||
         (fnamelen = (int)STRLEN(retval)) == 0) {
       vim_free(retval);
@@ -4756,8 +4754,6 @@ buf_modname (
   } else {
     fnamelen = (int)STRLEN(fname);
     retval = alloc((unsigned)(fnamelen + extlen + 3));
-    if (retval == NULL)
-      return NULL;
     STRCPY(retval, fname);
   }
 
@@ -6772,8 +6768,6 @@ static int do_autocmd_event(event_T event, char_u *pat, int nested, char_u *cmd,
         }
 
         ap = (AutoPat *)alloc((unsigned)sizeof(AutoPat));
-        if (ap == NULL)
-          return FAIL;
         ap->pat = vim_strnsave(pat, patlen);
         ap->patlen = patlen;
         if (ap->pat == NULL) {
@@ -6815,8 +6809,6 @@ static int do_autocmd_event(event_T event, char_u *pat, int nested, char_u *cmd,
       while ((ac = *prev_ac) != NULL)
         prev_ac = &ac->next;
       ac = (AutoCmd *)alloc((unsigned)sizeof(AutoCmd));
-      if (ac == NULL)
-        return FAIL;
       ac->cmd = vim_strsave(cmd);
       ac->scriptID = current_SID;
       if (ac->cmd == NULL) {

src/hardcopy.c

@@ -1596,8 +1596,6 @@ static int prt_find_resource(char *name, struct prt_ps_resource_S *resource)
   int retval;
 
   buffer = alloc(MAXPATHL + 1);
-  if (buffer == NULL)
-    return FALSE;
 
   vim_strncpy(resource->name, (char_u *)name, 63);
   /* Look for named resource file in runtimepath */

src/message.c

@@ -2941,12 +2941,8 @@ static char_u *msg_show_console_dialog(char_u *message, char_u *buttons, int dfl
        */
       vim_free(confirm_msg);
       confirm_msg = alloc(len);
-      if (confirm_msg == NULL)
-        return NULL;
       *confirm_msg = NUL;
       hotk = alloc(lenhotkey);
-      if (hotk == NULL)
-        return NULL;
 
       *confirm_msg = '\n';
       STRCPY(confirm_msg + 1, message);