patch 8.2.4588: mapping with key after other matching mapping does no…

…t work

Problem:    Mapping with key code after other matching mapping does not work.
Solution:   Change ">" to ">=". (closes #9903)

src/getchar.c

@@ -2416,6 +2416,7 @@ handle_mapping(
     mapblock_T	*mp_match;
     int		mp_match_len = 0;
     int		max_mlen = 0;
+    int		want_termcode = 0;  // 1 if termcode expected after max_mlen
     int		tb_c1;
     int		mlen;
 #ifdef FEAT_LANGMAP
@@ -2591,9 +2592,16 @@ handle_mapping(
 		}
 		else
 		    // No match; may have to check for termcode at next
-		    // character.
+		    // character.  If the first character that didn't match is
+		    // K_SPECIAL then check for a termcode.  This isn't perfect
+		    // but should work in most cases.
 		    if (max_mlen < mlen)
+		    {
 			max_mlen = mlen;
+			want_termcode = mp->m_keys[mlen] == K_SPECIAL;
+		    }
+		    else if (max_mlen == mlen && mp->m_keys[mlen] == K_SPECIAL)
+			want_termcode = 1;
 	    }
 	}
 
@@ -2646,7 +2654,7 @@ handle_mapping(
     // May check for a terminal code when there is no mapping or only a partial
     // mapping.  Also check if there is a full mapping with <Esc>, unless timed
     // out, since that is nearly always a partial match with a terminal code.
-    if ((mp == NULL || max_mlen > mp_match_len
+    if ((mp == NULL || max_mlen + want_termcode > mp_match_len
 		    || (mp_match_len == 1 && *mp->m_keys == ESC && !*timedout))
 	    && keylen != KEYLEN_PART_MAP)
     {

src/testdir/test_termcodes.vim

@@ -2111,6 +2111,15 @@ func Test_modifyOtherKeys_ambiguous_mapping()
 
   unmap <C-J>
   unmap <C-J>x
+
+  " if a special character is following there should be a check for a termcode
+  nnoremap s aX<Esc>
+  nnoremap s<BS> aY<Esc>
+  set t_kb=
+  call setline(1, 'x')
+  call feedkeys("s\x08", 'Lx!')
+  call assert_equal('xY', getline(1))
+
   set timeoutlen&
   bwipe!
 endfunc

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4588,
 /**/
     4587,
 /**/