patch 7.4.870v7.4.870

Problem:    May get into an invalid state when using getchar() in an
            expression mapping.
Solution:   Anticipate mod_mask to change. (idea by Yukihiro Nakadaira)

1 files changed, 4 insertions, 1 deletions

diff --git a/src/getchar.c b/src/getchar.c
index 87588a93ac..f4ec991b09 100644
--- a/src/getchar.c
+++ b/src/getchar.c
@@ -1630,13 +1630,16 @@ vgetc()
       last_recorded_len = 0;
       for (;;)			/* this is done twice if there are modifiers */
       {
+	int did_inc = FALSE;
+
 	if (mod_mask)		/* no mapping after modifier has been read */
 	{
 	    ++no_mapping;
 	    ++allow_keys;
+	    did_inc = TRUE;	/* mod_mask may change value */
 	}
 	c = vgetorpeek(TRUE);
-	if (mod_mask)
+	if (did_inc)
 	{
 	    --no_mapping;
 	    --allow_keys;