vim-patch:8.2.4959: using NULL regexp program (#21855)

Problem:    Using NULL regexp program.
Solution:   Check for regexp program becoming NULL in more places.

https://github.com/vim/vim/commit/b62dc5e7825bc195efe3041d5b3a9f1528359e1c

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

1 files changed, 15 insertions, 11 deletions

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 32e0cf5acf..9dd5fdaea5 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -2255,12 +2255,13 @@ int buflist_findpat(const char *pattern, const char *pattern_end, bool unlisted,
 
         regmatch_T regmatch;
         regmatch.regprog = vim_regcomp(p, magic_isset() ? RE_MAGIC : 0);
-        if (regmatch.regprog == NULL) {
-          xfree(pat);
-          return -1;
-        }
 
         FOR_ALL_BUFFERS_BACKWARDS(buf) {
+          if (regmatch.regprog == NULL) {
+            // invalid pattern, possibly after switching engine
+            xfree(pat);
+            return -1;
+          }
           if (buf->b_p_bl == find_listed
               && (!diffmode || diff_mode_buf(buf))
               && buflist_match(&regmatch, buf, false) != NULL) {
@@ -2372,12 +2373,6 @@ int ExpandBufnames(char *pat, int *num_file, char ***file, int options)
         break;            // there was no anchor, no need to try again
       }
       regmatch.regprog = vim_regcomp(patc + attempt * 11, RE_MAGIC);
-      if (regmatch.regprog == NULL) {
-        if (patc != pat) {
-          xfree(patc);
-        }
-        return FAIL;
-      }
     }
 
     int score = 0;
@@ -2398,6 +2393,13 @@ int ExpandBufnames(char *pat, int *num_file, char ***file, int options)
         }
 
         if (!fuzzy) {
+          if (regmatch.regprog == NULL) {
+            // invalid pattern, possibly after recompiling
+            if (patc != pat) {
+              xfree(patc);
+            }
+            return FAIL;
+          }
           p = buflist_match(&regmatch, buf, p_wic);
         } else {
           p = NULL;
@@ -2495,6 +2497,7 @@ int ExpandBufnames(char *pat, int *num_file, char ***file, int options)
 }
 
 /// Check for a match on the file name for buffer "buf" with regprog "prog".
+/// Note that rmp->regprog may become NULL when switching regexp engine.
 ///
 /// @param ignore_case  When true, ignore case. Use 'fic' otherwise.
 static char *buflist_match(regmatch_T *rmp, buf_T *buf, bool ignore_case)
@@ -2507,7 +2510,8 @@ static char *buflist_match(regmatch_T *rmp, buf_T *buf, bool ignore_case)
   return match;
 }
 
-/// Try matching the regexp in "prog" with file name "name".
+/// Try matching the regexp in "rmp->regprog" with file name "name".
+/// Note that rmp->regprog may become NULL when switching regexp engine.
 ///
 /// @param ignore_case  When true, ignore case. Use 'fileignorecase' otherwise.
 ///