patch 8.2.3935: CTRL-U in Insert mode does not fix the indent

Problem:    CTRL-U in Insert mode does not fix the indent.
Solution:   Fix the indent when 'cindent' is set.

src/edit.c

@@ -3980,6 +3980,9 @@ ins_bs(
     int		in_indent;
     int		oldState;
     int		cpc[MAX_MCO];	    // composing characters
+#if defined(FEAT_LISP) || defined(FEAT_CINDENT)
+    int		call_fix_indent = FALSE;
+#endif
 
     /*
      * can't delete anything in an empty file
@@ -4161,7 +4164,13 @@ ins_bs(
 	    save_col = curwin->w_cursor.col;
 	    beginline(BL_WHITE);
 	    if (curwin->w_cursor.col < save_col)
+	    {
 		mincol = curwin->w_cursor.col;
+#if defined(FEAT_LISP) || defined(FEAT_CINDENT)
+		// should now fix the indent to match with the previous line
+		call_fix_indent = TRUE;
+#endif
+	    }
 	    curwin->w_cursor.col = save_col;
 	}
 
@@ -4333,6 +4342,12 @@ ins_bs(
 #endif
     if (curwin->w_cursor.col <= 1)
 	did_ai = FALSE;
+
+#if defined(FEAT_LISP) || defined(FEAT_CINDENT)
+    if (call_fix_indent)
+	fix_indent();
+#endif
+
     /*
      * It's a little strange to put backspaces into the redo
      * buffer, but it makes auto-indent a lot easier to deal

src/testdir/test_textformat.vim

@@ -238,7 +238,7 @@ func Test_format_c_comment()
   END
   call assert_equal(expected, getline(1, '$'))
 
-  " Using "o" repeates the line comment, "O" does not.
+  " Using "o" repeats the line comment, "O" does not.
   %del
   let text =<< trim END
       nop;
@@ -261,6 +261,21 @@ func Test_format_c_comment()
   END
   call assert_equal(expected, getline(1, '$'))
 
+  " Using CTRL-U after "o" fixes the indent
+  %del
+  let text =<< trim END
+      {
+         val = val;      // This is a comment
+  END
+  call setline(1, text)
+  exe "normal! 2Go\<C-U>x\<Esc>"
+  let expected =<< trim END
+      {
+         val = val;      // This is a comment
+         x
+  END
+  call assert_equal(expected, getline(1, '$'))
+
   bwipe!
 endfunc
 

src/version.c

@@ -749,6 +749,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3935,
 /**/
     3934,
 /**/