vim-patch:8.2.5008: when 'formatoptions' contains "/" wrongly wrapping comment (#18717)

Problem:    When 'formatoptions' contains "/" wrongly wrapping a long trailing
            comment.
Solution:   Pass the OPENLINE_FORMAT flag.
7e66778815

src/nvim/change.c

@@ -1188,7 +1188,7 @@ int open_line(int dir, int flags, int second_line_indent, bool *did_do_comment)
   if (flags & OPENLINE_DO_COM) {
     lead_len = get_leader_len(saved_line, &lead_flags, dir == BACKWARD, true);
     if (lead_len == 0 && curbuf->b_p_cin && do_cindent && dir == FORWARD
-        && !has_format_option(FO_NO_OPEN_COMS)) {
+        && (!has_format_option(FO_NO_OPEN_COMS) || (flags & OPENLINE_FORMAT))) {
       // Check for a line comment after code.
       comment_start = check_linecomment(saved_line);
       if (comment_start != MAXCOL) {

src/nvim/change.h

@@ -5,11 +5,12 @@
 #include "nvim/pos.h"  // for linenr_T
 
 // flags for open_line()
-#define OPENLINE_DELSPACES  1   // delete spaces after cursor
+#define OPENLINE_DELSPACES  0x01  // delete spaces after cursor
-#define OPENLINE_DO_COM     2   // format comments
+#define OPENLINE_DO_COM     0x02  // format comments
-#define OPENLINE_KEEPTRAIL  4   // keep trailing spaces
+#define OPENLINE_KEEPTRAIL  0x04  // keep trailing spaces
-#define OPENLINE_MARKFIX    8   // fix mark positions
+#define OPENLINE_MARKFIX    0x08  // fix mark positions
-#define OPENLINE_COM_LIST  16   // format comments with list/2nd line indent
+#define OPENLINE_COM_LIST   0x10  // format comments with list/2nd line indent
+#define OPENLINE_FORMAT     0x20  // formatting long comment
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "change.h.generated.h"

src/nvim/edit.c

@@ -6246,6 +6246,7 @@ static void internal_format(int textwidth, int second_indent, int flags, int for
     open_line(FORWARD, OPENLINE_DELSPACES + OPENLINE_MARKFIX
               + (fo_white_par ? OPENLINE_KEEPTRAIL : 0)
               + (do_comments ? OPENLINE_DO_COM : 0)
+              + OPENLINE_FORMAT
               + ((flags & INSCHAR_COM_LIST) ? OPENLINE_COM_LIST : 0),
               ((flags & INSCHAR_COM_LIST) ? second_indent : old_indent),
               &did_do_comment);

src/nvim/testdir/test_textformat.vim

@@ -289,11 +289,28 @@ func Test_format_c_comment()
       x
   END
   call assert_equal(expected, getline(1, '$'))
+
+  " Comment is formatted when it wraps
+  normal 2GA with some more text added
+  let expected =<< trim END
+      nop;
+      val = val;      // This is a comment
+                      // with some more text
+                      // added
+      x
+  END
+  call assert_equal(expected, getline(1, '$'))
+
   set fo-=/
 
   " using 'indentexpr' instead of 'cindent' does not repeat a comment
   setl nocindent indentexpr=2
-  3delete
+  %del
+  let text =<< trim END
+      nop;
+      val = val;      // This is a comment
+  END
+  call setline(1, text)
   normal 2Gox
   let expected =<< trim END
       nop;