vim-patch:8.2.0035: saving and restoring called_emsg is clumsy (#19335)

Problem:    Saving and restoring called_emsg is clumsy.
Solution:   Count the number of error messages.
53989554a4

src/nvim/buffer.c

@@ -3136,18 +3136,16 @@ void maketitle(void)
     if (*p_titlestring != NUL) {
       if (stl_syntax & STL_IN_TITLE) {
         int use_sandbox = false;
-        int save_called_emsg = called_emsg;
+        const int called_emsg_before = called_emsg;
 
         use_sandbox = was_set_insecurely(curwin, "titlestring", 0);
-        called_emsg = false;
         build_stl_str_hl(curwin, buf, sizeof(buf),
                          (char *)p_titlestring, use_sandbox,
                          0, maxlen, NULL, NULL);
         title_str = buf;
-        if (called_emsg) {
+        if (called_emsg > called_emsg_before) {
           set_string_option_direct("titlestring", -1, "", OPT_FREE, SID_ERROR);
         }
-        called_emsg |= save_called_emsg;
       } else {
         title_str = (char *)p_titlestring;
       }
@@ -3252,17 +3250,15 @@ void maketitle(void)
     if (*p_iconstring != NUL) {
       if (stl_syntax & STL_IN_ICON) {
         int use_sandbox = false;
-        int save_called_emsg = called_emsg;
+        const int called_emsg_before = called_emsg;
 
         use_sandbox = was_set_insecurely(curwin, "iconstring", 0);
-        called_emsg = false;
         build_stl_str_hl(curwin, icon_str, sizeof(buf),
                          (char *)p_iconstring, use_sandbox,
                          0, 0, NULL, NULL);
-        if (called_emsg) {
+        if (called_emsg > called_emsg_before) {
           set_string_option_direct("iconstring", -1, "", OPT_FREE, SID_ERROR);
         }
-        called_emsg |= save_called_emsg;
       } else {
         icon_str = (char *)p_iconstring;
       }

src/nvim/eval.c

@@ -7296,7 +7296,7 @@ void timer_due_cb(TimeWatcher *tw, void *data)
 {
   timer_T *timer = (timer_T *)data;
   int save_did_emsg = did_emsg;
-  int save_called_emsg = called_emsg;
+  const int called_emsg_before = called_emsg;
   const bool save_ex_pressedreturn = get_pressedreturn();
 
   if (timer->stopped || timer->paused) {
@@ -7313,19 +7313,17 @@ void timer_due_cb(TimeWatcher *tw, void *data)
   argv[0].v_type = VAR_NUMBER;
   argv[0].vval.v_number = timer->timer_id;
   typval_T rettv = TV_INITIAL_VALUE;
-  called_emsg = false;
 
   callback_call(&timer->callback, 1, argv, &rettv);
 
   // Handle error message
-  if (called_emsg && did_emsg) {
+  if (called_emsg > called_emsg_before && did_emsg) {
     timer->emsg_count++;
     if (current_exception != NULL) {
       discard_current_exception();
     }
   }
   did_emsg = save_did_emsg;
-  called_emsg = save_called_emsg;
   set_pressedreturn(save_ex_pressedreturn);
 
   if (timer->emsg_count >= 3) {

src/nvim/eval/funcs.c

@@ -3902,15 +3902,14 @@ static void f_wait(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   typval_T argv = TV_INITIAL_VALUE;
   typval_T exprval = TV_INITIAL_VALUE;
   bool error = false;
-  int save_called_emsg = called_emsg;
+  const int called_emsg_before = called_emsg;
-  called_emsg = false;
 
   LOOP_PROCESS_EVENTS_UNTIL(&main_loop, main_loop.events, timeout,
                             eval_expr_typval(&expr, &argv, 0, &exprval) != OK
                             || tv_get_number_chk(&exprval, &error)
-                            || called_emsg || error || got_int);
+                            || called_emsg > called_emsg_before || error || got_int);
 
-  if (called_emsg || error) {
+  if (called_emsg > called_emsg_before || error) {
     rettv->vval.v_number = -3;
   } else if (got_int) {
     got_int = false;
@@ -3920,8 +3919,6 @@ static void f_wait(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     rettv->vval.v_number = 0;
   }
 
-  called_emsg = save_called_emsg;
-
   // Stop dummy timer
   time_watcher_stop(tw);
   time_watcher_close(tw, dummy_timer_close_cb);

src/nvim/globals.h

@@ -229,7 +229,7 @@ EXTERN bool did_emsg;                       // set by emsg() when the message
 EXTERN bool called_vim_beep;                // set if vim_beep() is called
 EXTERN bool did_emsg_syntax;                // did_emsg set because of a
                                             // syntax error
-EXTERN int called_emsg;                     // always set by emsg()
+EXTERN int called_emsg;                     // always incremented by emsg()
 EXTERN int ex_exitval INIT(= 0);            // exit value for ex mode
 EXTERN bool emsg_on_display INIT(= false);  // there is an error message
 EXTERN bool rc_did_emsg INIT(= false);      // vim_regcomp() called emsg()

src/nvim/match.c

@@ -398,7 +398,7 @@ static void next_search_hl(win_T *win, match_T *search_hl, match_T *shl, linenr_
   linenr_T l;
   colnr_T matchcol;
   long nmatched = 0;
-  int save_called_emsg = called_emsg;
+  const int called_emsg_before = called_emsg;
 
   // for :{range}s/pat only highlight inside the range
   if (lnum < search_first_line || lnum > search_last_line) {
@@ -421,7 +421,6 @@ static void next_search_hl(win_T *win, match_T *search_hl, match_T *shl, linenr_
 
   // Repeat searching for a match until one is found that includes "mincol"
   // or none is found in this line.
-  called_emsg = false;
   for (;;) {
     // Stop searching after passing the time limit.
     if (profile_passed_limit(shl->tm)) {
@@ -468,7 +467,7 @@ static void next_search_hl(win_T *win, match_T *search_hl, match_T *shl, linenr_
       if (regprog_is_copy) {
         cur->match.regprog = cur->hl.rm.regprog;
       }
-      if (called_emsg || got_int || timed_out) {
+      if (called_emsg > called_emsg_before || got_int || timed_out) {
         // Error while handling regexp: stop using this regexp.
         if (shl == search_hl) {
           // don't free regprog in the match list, it's a copy
@@ -495,9 +494,6 @@ static void next_search_hl(win_T *win, match_T *search_hl, match_T *shl, linenr_
       break;                            // useful match found
     }
   }
-
-  // Restore called_emsg for assert_fails().
-  called_emsg = save_called_emsg;
 }
 
 /// Advance to the match in window "wp" line "lnum" or past it.

src/nvim/message.c

@@ -637,7 +637,7 @@ static bool emsg_multiline(const char *s, bool multiline)
     return true;
   }
 
-  called_emsg = true;
+  called_emsg++;
 
   // If "emsg_severe" is true: When an error exception is to be thrown,
   // prefer this message over previous messages for the same command.

src/nvim/regexp.c

@@ -2327,7 +2327,6 @@ regprog_T *vim_regcomp(char *expr_arg, int re_flags)
 {
   regprog_T *prog = NULL;
   char_u *expr = (char_u *)expr_arg;
-  int save_called_emsg;
 
   regexp_engine = p_re;
 
@@ -2360,8 +2359,7 @@ regprog_T *vim_regcomp(char *expr_arg, int re_flags)
   //
   // First try the NFA engine, unless backtracking was requested.
   //
-  save_called_emsg = called_emsg;
+  const int called_emsg_before = called_emsg;
-  called_emsg = false;
   if (regexp_engine != BACKTRACKING_ENGINE) {
     prog = nfa_regengine.regcomp(expr,
                                  re_flags + (regexp_engine == AUTOMATIC_ENGINE ? RE_AUTO : 0));
@@ -2388,13 +2386,12 @@ regprog_T *vim_regcomp(char *expr_arg, int re_flags)
     // also fails for patterns that it can't handle well but are still valid
     // patterns, thus a retry should work.
     // But don't try if an error message was given.
-    if (regexp_engine == AUTOMATIC_ENGINE && !called_emsg) {
+    if (regexp_engine == AUTOMATIC_ENGINE && called_emsg == called_emsg_before) {
       regexp_engine = BACKTRACKING_ENGINE;
       report_re_switch(expr);
       prog = bt_regengine.regcomp(expr, re_flags);
     }
   }
-  called_emsg |= save_called_emsg;
 
   if (prog != NULL) {
     // Store the info needed to call regcomp() again when the engine turns out

src/nvim/screen.c

@@ -6533,13 +6533,11 @@ static void win_redr_ruler(win_T *wp, bool always)
   }
 
   if (*p_ruf && p_ch > 0 && !ui_has(kUIMessages)) {
-    int save_called_emsg = called_emsg;
+    const int called_emsg_before = called_emsg;
-    called_emsg = false;
     win_redr_custom(wp, false, true);
-    if (called_emsg) {
+    if (called_emsg > called_emsg_before) {
       set_string_option_direct("rulerformat", -1, "", OPT_FREE, SID_ERROR);
     }
-    called_emsg |= save_called_emsg;
     return;
   }
 

src/nvim/search.c

@@ -556,7 +556,7 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
   long nmatched;
   int submatch = 0;
   bool first_match = true;
-  int save_called_emsg = called_emsg;
+  const int called_emsg_before = called_emsg;
   bool break_loop = false;
   linenr_T stop_lnum = 0;  // stop after this line number when != 0
   proftime_T *tm = NULL;   // timeout limit or NULL
@@ -579,7 +579,6 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
   /*
    * find the string
    */
-  called_emsg = FALSE;
   do {  // loop for count
     // When not accepting a match at the start position set "extra_col" to a
     // non-zero value.  Don't do that when starting at MAXCOL, since MAXCOL + 1
@@ -651,7 +650,7 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
           break;
         }
         // Abort searching on an error (e.g., out of stack).
-        if (called_emsg || (timed_out != NULL && *timed_out)) {
+        if (called_emsg > called_emsg_before || (timed_out != NULL && *timed_out)) {
           break;
         }
         if (nmatched > 0) {
@@ -908,7 +907,8 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
       // Stop the search if wrapscan isn't set, "stop_lnum" is
       // specified, after an interrupt, after a match and after looping
       // twice.
-      if (!p_ws || stop_lnum != 0 || got_int || called_emsg
+      if (!p_ws || stop_lnum != 0 || got_int
+          || called_emsg > called_emsg_before
           || (timed_out != NULL && *timed_out)
           || break_loop
           || found || loop) {
@@ -933,7 +933,7 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
         extra_arg->sa_wrapped = true;
       }
     }
-    if (got_int || called_emsg
+    if (got_int || called_emsg > called_emsg_before
         || (timed_out != NULL && *timed_out)
         || break_loop) {
       break;
@@ -942,8 +942,6 @@ int searchit(win_T *win, buf_T *buf, pos_T *pos, pos_T *end_pos, Direction dir,
 
   vim_regfree(regmatch.regprog);
 
-  called_emsg |= save_called_emsg;
-
   if (!found) {             // did not find it
     if (got_int) {
       emsg(_(e_interr));
@@ -4409,7 +4407,7 @@ static int is_zero_width(char_u *pattern, int move, pos_T *cur, Direction direct
   int nmatched = 0;
   int result = -1;
   pos_T pos;
-  int save_called_emsg = called_emsg;
+  const int called_emsg_before = called_emsg;
   int flag = 0;
 
   if (pattern == NULL) {
@@ -4435,7 +4433,6 @@ static int is_zero_width(char_u *pattern, int move, pos_T *cur, Direction direct
                SEARCH_KEEP + flag, RE_SEARCH, NULL) != FAIL) {
     // Zero-width pattern should match somewhere, then we can check if
     // start and end are in the same position.
-    called_emsg = false;
     do {
       regmatch.startpos[0].col++;
       nmatched = vim_regexec_multi(&regmatch, curwin, curbuf,
@@ -4449,14 +4446,13 @@ static int is_zero_width(char_u *pattern, int move, pos_T *cur, Direction direct
              ? regmatch.startpos[0].col < pos.col
              : regmatch.startpos[0].col > pos.col);
 
-    if (!called_emsg) {
+    if (called_emsg == called_emsg_before) {
       result = (nmatched != 0
                 && regmatch.startpos[0].lnum == regmatch.endpos[0].lnum
                 && regmatch.startpos[0].col == regmatch.endpos[0].col);
     }
   }
 
-  called_emsg |= save_called_emsg;
   vim_regfree(regmatch.regprog);
   return result;
 }

src/nvim/testing.c

@@ -405,15 +405,15 @@ void f_assert_fails(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   const char *const cmd = tv_get_string_chk(&argvars[0]);
   garray_T ga;
   int save_trylevel = trylevel;
+  const int called_emsg_before = called_emsg;
 
   // trylevel must be zero for a ":throw" command to be considered failed
   trylevel = 0;
-  called_emsg = false;
   suppress_errthrow = true;
   emsg_silent = true;
 
   do_cmdline_cmd(cmd);
-  if (!called_emsg) {
+  if (called_emsg == called_emsg_before) {
     prepare_assert_error(&ga);
     ga_concat(&ga, "command did not fail: ");
     assert_append_cmd_or_arg(&ga, argvars, cmd);
@@ -438,7 +438,6 @@ void f_assert_fails(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   }
 
   trylevel = save_trylevel;
-  called_emsg = false;
   suppress_errthrow = false;
   emsg_silent = false;
   emsg_on_display = false;