patch 8.2.4534: Vim9: "is" operator with empty string and null returns true
Problem: Vim9: "is" operator with empty string and null returns true.
Solution: Consider empty string and null to be different for "is".
diff --git a/src/typval.c b/src/typval.c
index 53512c6..e0511be 100644
--- a/src/typval.c
+++ b/src/typval.c
@@ -1583,9 +1583,23 @@
i = ic ? MB_STRICMP(s1, s2) : STRCMP(s1, s2);
switch (type)
{
- case EXPR_IS:
+ case EXPR_IS: if (in_vim9script())
+ {
+ // Really check it is the same string, not just
+ // the same value.
+ val = tv1->vval.v_string == tv2->vval.v_string;
+ break;
+ }
+ // FALLTHROUGH
case EXPR_EQUAL: val = (i == 0); break;
- case EXPR_ISNOT:
+ case EXPR_ISNOT: if (in_vim9script())
+ {
+ // Really check it is not the same string, not
+ // just a different value.
+ val = tv1->vval.v_string != tv2->vval.v_string;
+ break;
+ }
+ // FALLTHROUGH
case EXPR_NEQUAL: val = (i != 0); break;
case EXPR_GREATER: val = (i > 0); break;
case EXPR_GEQUAL: val = (i >= 0); break;