vim-patch:9.1.0804: tests: no error check when setting global 'cc'

Problem:  tests: no error check when setting global 'cc'
Solution: also parse and check global 'cc' value (Milly)

closes: vim/vim#15914

https://github.com/vim/vim/commit/a441a3eaabbfc14b4772e07ecbecaaff3bd06a58

Co-authored-by: Milly <milly.ca@gmail.com>

5 files changed, 38 insertions, 19 deletions

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index ce47705aa6..2142b5b298 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -255,7 +255,7 @@ int open_buffer(bool read_stdin, exarg_T *eap, int flags_arg)
     emsg(_("E83: Cannot allocate buffer, using other one..."));
     enter_buffer(curbuf);
     if (old_tw != curbuf->b_p_tw) {
-      check_colorcolumn(curwin);
+      check_colorcolumn(NULL, curwin);
     }
     return FAIL;
   }
@@ -1029,7 +1029,7 @@ void handle_swap_exists(bufref_T *old_curbuf)
       enter_buffer(buf);
 
       if (old_tw != curbuf->b_p_tw) {
-        check_colorcolumn(curwin);
+        check_colorcolumn(NULL, curwin);
       }
     }
     // If "old_curbuf" is NULL we are in big trouble here...
@@ -1669,7 +1669,7 @@ void set_curbuf(buf_T *buf, int action, bool update_jumplist)
     // enter some buffer.  Using the last one is hopefully OK.
     enter_buffer(valid ? buf : lastbuf);
     if (old_tw != curbuf->b_p_tw) {
-      check_colorcolumn(curwin);
+      check_colorcolumn(NULL, curwin);
     }
   }
 
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 89753f7cf8..8e6e068e96 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -2592,7 +2592,7 @@ static const char *did_set_swapfile(optset_T *args)
 static const char *did_set_textwidth(optset_T *args FUNC_ATTR_UNUSED)
 {
   FOR_ALL_TAB_WINDOWS(tp, wp) {
-    check_colorcolumn(wp);
+    check_colorcolumn(NULL, wp);
   }
 
   return NULL;
@@ -5111,7 +5111,7 @@ void didset_window_options(win_T *wp, bool valid_cursor)
   } else {
     wp->w_skipcol = 0;
   }
-  check_colorcolumn(wp);
+  check_colorcolumn(NULL, wp);
   briopt_check(wp);
   fill_culopt_flags(NULL, wp);
   set_chars_option(wp, wp->w_p_fcs, kFillchars, true, NULL, 0);
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
index f9be1be3d2..0e63a8089d 100644
--- a/src/nvim/optionstr.c
+++ b/src/nvim/optionstr.c
@@ -898,7 +898,8 @@ int expand_set_clipboard(optexpand_T *args, int *numMatches, char ***matches)
 const char *did_set_colorcolumn(optset_T *args)
 {
   win_T *win = (win_T *)args->os_win;
-  return check_colorcolumn(win);
+  char **varp = (char **)args->os_varp;
+  return check_colorcolumn(*varp, varp == &win->w_p_cc ? win : NULL);
 }
 
 /// The 'comments' option is changed.
diff --git a/src/nvim/window.c b/src/nvim/window.c
index 91a69c3ec4..73d31d3048 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -7371,18 +7371,37 @@ static int int_cmp(const void *pa, const void *pb)
   return a == b ? 0 : a < b ? -1 : 1;
 }
 
-/// Handle setting 'colorcolumn' or 'textwidth' in window "wp".
+/// Check "cc" as 'colorcolumn' and update the members of "wp".
+/// This is called when 'colorcolumn' or 'textwidth' is changed.
+///
+/// @param cc  when NULL: use "wp->w_p_cc"
+/// @param wp  when NULL: only parse "cc"
 ///
 /// @return error message, NULL if it's OK.
-const char *check_colorcolumn(win_T *wp)
+const char *check_colorcolumn(char *cc, win_T *wp)
 {
-  if (wp->w_buffer == NULL) {
+  if (wp != NULL && wp->w_buffer == NULL) {
     return NULL;      // buffer was closed
   }
 
+  char *s;
+  if (cc != NULL) {
+    s = cc;
+  } else {
+    s = wp->w_p_cc;
+  }
+
+  OptInt tw;
+  if (wp != NULL) {
+    tw = wp->w_buffer->b_p_tw;
+  } else {
+    // buffer-local value not set, assume zero
+    tw = 0;
+  }
+
   unsigned count = 0;
   int color_cols[256];
-  for (char *s = wp->w_p_cc; *s != NUL && count < 255;) {
+  while (*s != NUL && count < 255) {
     int col;
     if (*s == '-' || *s == '+') {
       // -N and +N: add to 'textwidth'
@@ -7392,16 +7411,12 @@ const char *check_colorcolumn(win_T *wp)
         return e_invarg;
       }
       col = col * getdigits_int(&s, true, 0);
-      if (wp->w_buffer->b_p_tw == 0) {
+      if (tw == 0) {
         goto skip;          // 'textwidth' not set, skip this item
       }
-      assert((col >= 0
-              && wp->w_buffer->b_p_tw <= INT_MAX - col
-              && wp->w_buffer->b_p_tw + col >= INT_MIN)
-             || (col < 0
-                 && wp->w_buffer->b_p_tw >= INT_MIN - col
-                 && wp->w_buffer->b_p_tw + col <= INT_MAX));
-      col += (int)wp->w_buffer->b_p_tw;
+      assert((col >= 0 && tw <= INT_MAX - col && tw + col >= INT_MIN)
+             || (col < 0 && tw >= INT_MIN - col && tw + col <= INT_MAX));
+      col += (int)tw;
       if (col < 0) {
         goto skip;
       }
@@ -7423,6 +7438,10 @@ skip:
     }
   }
 
+  if (wp == NULL) {
+    return NULL;  // only parse "cc"
+  }
+
   xfree(wp->w_p_cc_cols);
   if (count == 0) {
     wp->w_p_cc_cols = NULL;
diff --git a/test/old/testdir/gen_opt_test.vim b/test/old/testdir/gen_opt_test.vim
index 8a6d534c62..c28284afdf 100644
--- a/test/old/testdir/gen_opt_test.vim
+++ b/test/old/testdir/gen_opt_test.vim
@@ -46,7 +46,6 @@ let skip_setglobal_reasons = #{
       \ iminsert: 'The global value is always overwritten by the local value',
       \ imsearch: 'The global value is always overwritten by the local value',
       \ breakindentopt:	'TODO: fix missing error handling for setglobal',
-      \ colorcolumn:	'TODO: fix missing error handling for setglobal',
       \ conceallevel:	'TODO: fix missing error handling for setglobal',
       \ foldcolumn:	'TODO: fix missing error handling for setglobal',
       \ numberwidth:	'TODO: fix missing error handling for setglobal',