vim-patch:8.2.4029: debugging NFA regexp my crash, cached indent may be wrong

Problem:    Debugging NFA regexp my crash, cached indent may be wrong.
Solution:   Fix some debug warnings in the NFA regexp code.  Make sure log_fd
            is set when used.  Fix breakindent and indent caching. (Christian
            Brabandt, closes vim/vim#9482)
https://github.com/vim/vim/commit/b2d85e3784ac89f5209489844c1ee0f54d117abb

3 files changed, 65 insertions, 37 deletions

diff --git a/src/nvim/indent.c b/src/nvim/indent.c
index cb5819e946..c929a0d14a 100644
--- a/src/nvim/indent.c
+++ b/src/nvim/indent.c
@@ -783,19 +783,22 @@ int get_breakindent_win(win_T *wp, char_u *line)
   FUNC_ATTR_NONNULL_ALL
 {
   static int prev_indent = 0;  // Cached indent value.
-  static long prev_ts = 0;  // Cached tabstop value.
+  static long prev_ts = 0L;  // Cached tabstop value.
   static const char_u *prev_line = NULL;  // cached pointer to line.
   static varnumber_T prev_tick = 0;  // Changedtick of cached value.
-  static long *prev_vts = NULL;    // Cached vartabs values.
+  static long *prev_vts = NULL;  // Cached vartabs values.
+  static int prev_list = 0;  // cached list value
+  static int prev_listopt = 0;  // cached w_p_briopt_list value
   int bri = 0;
   // window width minus window margin space, i.e. what rests for text
   const int eff_wwidth = wp->w_width_inner -
                          ((wp->w_p_nu || wp->w_p_rnu)
                           && (vim_strchr(p_cpo, CPO_NUMCOL) == NULL) ? number_width(wp) + 1 : 0);
 
-  // used cached indent, unless pointer or 'tabstop' changed
+  // used cached indent, unless line, 'tabstop' or briopt_list changed
   if (prev_line != line || prev_ts != wp->w_buffer->b_p_ts
       || prev_tick != buf_get_changedtick(wp->w_buffer)
+      || prev_listopt != wp->w_briopt_list
       || prev_vts != wp->w_buffer->b_p_vts_array) {
     prev_line = line;
     prev_ts = wp->w_buffer->b_p_ts;
@@ -805,6 +808,25 @@ int get_breakindent_win(win_T *wp, char_u *line)
                                       wp->w_buffer->b_p_ts,
                                       wp->w_buffer->b_p_vts_array,
                                       wp->w_p_list);
+    prev_listopt = wp->w_briopt_list;
+    // add additional indent for numbered lists
+    if (wp->w_briopt_list != 0) {
+      regmatch_T regmatch = {
+        .regprog = vim_regcomp(curbuf->b_p_flp,
+                               RE_MAGIC + RE_STRING + RE_AUTO + RE_STRICT),
+      };
+      if (regmatch.regprog != NULL) {
+        regmatch.rm_ic = false;
+        if (vim_regexec(&regmatch, (char *)line, 0)) {
+          if (wp->w_briopt_list > 0) {
+            prev_list += wp->w_briopt_list;
+          } else {
+            prev_list = (int)(*regmatch.endp - *regmatch.startp);
+          }
+        }
+        vim_regfree(regmatch.regprog);
+      }
+    }
   }
   bri = prev_indent + wp->w_briopt_shift;
 
@@ -813,21 +835,10 @@ int get_breakindent_win(win_T *wp, char_u *line)
 
   // add additional indent for numbered lists
   if (wp->w_briopt_list != 0) {
-    regmatch_T regmatch = {
-      .regprog = vim_regcomp(curbuf->b_p_flp,
-                             RE_MAGIC + RE_STRING + RE_AUTO + RE_STRICT),
-    };
-
-    if (regmatch.regprog != NULL) {
-      regmatch.rm_ic = false;
-      if (vim_regexec(&regmatch, (char *)line, 0)) {
-        if (wp->w_briopt_list > 0) {
-          bri += wp->w_briopt_list;
-        } else {
-          bri = (int)(*regmatch.endp - *regmatch.startp);
-        }
-      }
-      vim_regfree(regmatch.regprog);
+    if (wp->w_briopt_list > 0) {
+      bri += prev_list;
+    } else {
+      bri = prev_list;
     }
   }
 
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
index 43628d2842..65bc9f60df 100644
--- a/src/nvim/optionstr.c
+++ b/src/nvim/optionstr.c
@@ -697,6 +697,10 @@ char *did_set_string_option(int opt_idx, char **varp, char *oldval, char *errbuf
     if (briopt_check(curwin) == FAIL) {
       errmsg = e_invarg;
     }
+    // list setting requires a redraw
+    if (curwin->w_briopt_list) {
+      redraw_all_later(UPD_NOT_VALID);
+    }
   } else if (varp == &p_isi
              || varp == &(curbuf->b_p_isk)
              || varp == &p_isp
@@ -1601,6 +1605,12 @@ char *did_set_string_option(int opt_idx, char **varp, char *oldval, char *errbuf
     setmouse();  // in case 'mouse' changed
   }
 
+  // Changing Formatlistpattern when briopt includes the list setting:
+  // redraw
+  if ((varp == &p_flp || varp == &(curbuf->b_p_flp)) && curwin->w_briopt_list) {
+    redraw_all_later(UPD_NOT_VALID);
+  }
+
   if (curwin->w_curswant != MAXCOL
       && (opt->flags & (P_CURSWANT | P_RALL)) != 0) {
     curwin->w_set_curswant = true;
diff --git a/src/nvim/regexp_nfa.c b/src/nvim/regexp_nfa.c
index 2f4b1b98c1..d4d2ed28cc 100644
--- a/src/nvim/regexp_nfa.c
+++ b/src/nvim/regexp_nfa.c
@@ -3370,8 +3370,8 @@ static void nfa_print_state2(FILE *debugf, nfa_state_T *state, garray_T *indent)
     int last = indent->ga_len - 3;
     char_u save[2];
 
-    STRNCPY(save, &p[last], 2);
-    STRNCPY(&p[last], "+-", 2);
+    STRNCPY(save, &p[last], 2);  // NOLINT(runtime/printf)
+    memcpy(&p[last], "+-", 2);
     fprintf(debugf, " %s", p);
     STRNCPY(&p[last], save, 2);  // NOLINT(runtime/printf)
   } else {
@@ -4635,6 +4635,20 @@ static bool sub_equal(regsub_T *sub1, regsub_T *sub2)
 }
 
 #ifdef REGEXP_DEBUG
+static void open_debug_log(TriState result)
+{
+  log_fd = fopen(NFA_REGEXP_RUN_LOG, "a");
+  if (log_fd == NULL) {
+    emsg(_(e_log_open_failed));
+    log_fd = stderr;
+  }
+
+  fprintf(log_fd, "****************************\n");
+  fprintf(log_fd, "FINISHED RUNNING nfa_regmatch() recursively\n");
+  fprintf(log_fd, "MATCH = %s\n", result == kTrue ? "OK" : result == kNone ? "MAYBE" : "FALSE");
+  fprintf(log_fd, "****************************\n");
+}
+
 static void report_state(char *action, regsub_T *sub, nfa_state_T *state, int lid, nfa_pim_T *pim)
 {
   int col;
@@ -4647,6 +4661,9 @@ static void report_state(char *action, regsub_T *sub, nfa_state_T *state, int li
     col = (int)(sub->list.line[0].start - rex.line);
   }
   nfa_set_code(state->c);
+  if (log_fd == NULL) {
+    open_debug_log(kNone);
+  }
   fprintf(log_fd, "> %s state %d to list %d. char %d: %s (start col %d)%s\n",
           action, abs(state->id), lid, state->c, code, col,
           pim_info(pim));
@@ -5668,16 +5685,7 @@ static int recursive_regmatch(nfa_state_T *state, nfa_pim_T *pim, nfa_regprog_T
   nfa_endp = save_nfa_endp;
 
 #ifdef REGEXP_DEBUG
-  log_fd = fopen(NFA_REGEXP_RUN_LOG, "a");
-  if (log_fd != NULL) {
-    fprintf(log_fd, "****************************\n");
-    fprintf(log_fd, "FINISHED RUNNING nfa_regmatch() recursively\n");
-    fprintf(log_fd, "MATCH = %s\n", !result ? "false" : "OK");
-    fprintf(log_fd, "****************************\n");
-  } else {
-    emsg(_(e_log_open_failed));
-    log_fd = stderr;
-  }
+  open_debug_log(result);
 #endif
 
   return result;
@@ -5983,16 +5991,15 @@ static int nfa_regmatch(nfa_regprog_T *prog, nfa_state_T *start, regsubs_T *subm
 
 #ifdef REGEXP_DEBUG
   log_fd = fopen(NFA_REGEXP_RUN_LOG, "a");
-  if (log_fd != NULL) {
-    fprintf(log_fd, "**********************************\n");
-    nfa_set_code(start->c);
-    fprintf(log_fd, " RUNNING nfa_regmatch() starting with state %d, code %s\n",
-            abs(start->id), code);
-    fprintf(log_fd, "**********************************\n");
-  } else {
+  if (log_fd == NULL) {
     emsg(_(e_log_open_failed));
     log_fd = stderr;
   }
+  fprintf(log_fd, "**********************************\n");
+  nfa_set_code(start->c);
+  fprintf(log_fd, " RUNNING nfa_regmatch() starting with state %d, code %s\n",
+          abs(start->id), code);
+  fprintf(log_fd, "**********************************\n");
 #endif
 
   thislist = &list[0];