patch 8.2.4203: entering a character with CTRL-V may include modifiers

Problem:    Entering a character with CTRL-V may include modifiers.
Solution:   Reset "mod_mask" when entering a character with digits after
            CTRL-V. (closes #9610)

src/edit.c

@@ -1909,6 +1909,11 @@ get_literal(int noReduceKeys)
 	if ((nc == ESC || nc == CSI) && !noReduceKeys)
 	    nc = decodeModifyOtherKeys(nc);
 
+	if ((mod_mask & ~MOD_MASK_SHIFT) != 0)
+	    // A character with non-Shift modifiers should not be a valid
+	    // character for i_CTRL-V_digit.
+	    break;
+
 #ifdef FEAT_CMDL_INFO
 	if (!(State & CMDLINE) && MB_BYTE2LEN_CHECK(nc) == 1)
 	    add_to_showcmd(nc);
@@ -1986,7 +1991,11 @@ get_literal(int noReduceKeys)
 	--allow_keys;
 #endif
     if (nc)
+    {
 	vungetc(nc);
+	// A character typed with i_CTRL-V_digit cannot have modifiers.
+	mod_mask = 0;
+    }
     got_int = FALSE;	    // CTRL-C typed after CTRL-V is not an interrupt
     return cc;
 }

src/testdir/test_edit.vim

@@ -1073,14 +1073,16 @@ func Test_edit_DROP()
 endfunc
 
 func Test_edit_CTRL_V()
-  CheckFeature ebcdic
+  CheckNotFeature ebcdic
+
   new
   call setline(1, ['abc'])
   call cursor(2, 1)
+
   " force some redraws
   set showmode showcmd
-  "call test_override_char_avail(1)
-  call test_override('ALL', 1)
+  call test_override('char_avail', 1)
+
   call feedkeys("A\<c-v>\<c-n>\<c-v>\<c-l>\<c-v>\<c-b>\<esc>", 'tnix')
   call assert_equal(["abc\x0e\x0c\x02"], getline(1, '$'))
 
@@ -1093,8 +1095,19 @@ func Test_edit_CTRL_V()
     set norl
   endif
 
-  call test_override('ALL', 0)
   set noshowmode showcmd
+  call test_override('char_avail', 0)
+
+  " No modifiers should be applied to the char typed using i_CTRL-V_digit.
+  call feedkeys(":append\<CR>\<C-V>76c\<C-V>76\<C-F2>\<C-V>u3c0j\<C-V>u3c0\<M-F3>\<CR>.\<CR>", 'tnix')
+  call assert_equal('LcL<C-F2>πjπ<M-F3>', getline(2))
+
+  if has('osx')
+    " A char with a modifier should not be a valid char for i_CTRL-V_digit.
+    call feedkeys("o\<C-V>\<D-j>\<C-V>\<D-1>\<C-V>\<D-o>\<C-V>\<D-x>\<C-V>\<D-u>", 'tnix')
+    call assert_equal('<D-j><D-1><D-o><D-x><D-u>', getline(3))
+  endif
+
   bw!
 endfunc
 

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4203,
 /**/
     4202,
 /**/