vim-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 vim/vim#9610)
https://github.com/vim/vim/commit/502d8ae3e8ed8b6f8dd2ff175f154f9aa87228ef

Commenting out test_override() as before.

Commenting out part of CheckNotFeature() because Vim patch 8.2.0427
cannot be ported without breaking a lot of oldtests that check for
removed features.

3 files changed, 28 insertions, 11 deletions

diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index a9c606ec13..f3226d4f6c 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -5631,8 +5631,12 @@ int get_literal(void)
   i = 0;
   for (;;) {
     nc = plain_vgetc();
-    if (!(State & CMDLINE)
-        && MB_BYTE2LEN_CHECK(nc) == 1) {
+    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;
+    }
+    if (!(State & CMDLINE) && MB_BYTE2LEN_CHECK(nc) == 1) {
       add_to_showcmd(nc);
     }
     if (nc == 'x' || nc == 'X') {
@@ -5698,6 +5702,8 @@ int get_literal(void)
   --no_mapping;
   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;
diff --git a/src/nvim/testdir/check.vim b/src/nvim/testdir/check.vim
index 14bab33a2f..ab26dddbe0 100644
--- a/src/nvim/testdir/check.vim
+++ b/src/nvim/testdir/check.vim
@@ -12,9 +12,9 @@ endfunc
 " Command to check for the absence of a feature.
 command -nargs=1 CheckNotFeature call CheckNotFeature(<f-args>)
 func CheckNotFeature(name)
-  if !has(a:name, 1)
-    throw 'Checking for non-existent feature ' .. a:name
-  endif
+  " if !has(a:name, 1)
+  "   throw 'Checking for non-existent feature ' .. a:name
+  " endif
   if has(a:name)
     throw 'Skipped: ' .. a:name .. ' feature present'
   endif
diff --git a/src/nvim/testdir/test_edit.vim b/src/nvim/testdir/test_edit.vim
index fc4e80f0d6..c1f74e7675 100644
--- a/src/nvim/testdir/test_edit.vim
+++ b/src/nvim/testdir/test_edit.vim
@@ -1006,16 +1006,16 @@ func Test_edit_DROP()
 endfunc
 
 func Test_edit_CTRL_V()
-  if has("ebcdic")
-    return
-  endif
+  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, '$'))
 
@@ -1028,8 +1028,19 @@ 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