vim-patch:9.1.0997: too many strlen() calls in drawscreen.c (#31927)

Problem:  too many strlen() calls in drawscreen.c
Solution: refactor drawscreen.c and remove calls to strlen(),
          make get_keymap_str() (in screen.c) return string length
          instead of TRUE/FALSE (John Marriott).

https://github.com/vim/vim/commit/a21240b97debea2e087aee6ad1488b5f075d1259

Co-authored-by: John Marriott <basilisk@internode.on.net>

1 files changed, 10 insertions, 7 deletions

diff --git a/src/nvim/digraph.c b/src/nvim/digraph.c
index aaa77f5fcf..326e929fb6 100644
--- a/src/nvim/digraph.c
+++ b/src/nvim/digraph.c
@@ -2183,22 +2183,22 @@ static void keymap_unload(void)
 /// @param fmt  format string containing one %s item
 /// @param buf  buffer for the result
 /// @param len  length of buffer
-bool get_keymap_str(win_T *wp, char *fmt, char *buf, int len)
+int get_keymap_str(win_T *wp, char *fmt, char *buf, int len)
 {
   char *p;
 
   if (wp->w_buffer->b_p_iminsert != B_IMODE_LMAP) {
-    return false;
+    return 0;
   }
 
   buf_T *old_curbuf = curbuf;
   win_T *old_curwin = curwin;
+  char to_evaluate[] = "b:keymap_name";
 
   curbuf = wp->w_buffer;
   curwin = wp;
-  STRCPY(buf, "b:keymap_name");       // must be writable
   emsg_skip++;
-  char *s = p = eval_to_string(buf, false, false);
+  char *s = p = eval_to_string(to_evaluate, false, false);
   emsg_skip--;
   curbuf = old_curbuf;
   curwin = old_curwin;
@@ -2209,9 +2209,12 @@ bool get_keymap_str(win_T *wp, char *fmt, char *buf, int len)
       p = "lang";
     }
   }
-  if (vim_snprintf(buf, (size_t)len, fmt, p) > len - 1) {
+  int plen = vim_snprintf(buf, (size_t)len, fmt, p);
+  xfree(s);
+  if (plen < 0 || plen > len - 1) {
     buf[0] = NUL;
+    plen = 0;
   }
-  xfree(s);
-  return buf[0] != NUL;
+
+  return plen;
 }