reflect: don't panic on delete from nil map.
Fixes #8051
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/95560046
diff --git a/src/pkg/reflect/all_test.go b/src/pkg/reflect/all_test.go
index 9c5eb4e..e994901 100644
--- a/src/pkg/reflect/all_test.go
+++ b/src/pkg/reflect/all_test.go
@@ -993,6 +993,9 @@
if x.Kind() != Invalid {
t.Errorf("mbig.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x)
}
+
+ // Test that deletes from a nil map succeed.
+ mv.SetMapIndex(ValueOf("hi"), Value{})
}
func TestChan(t *testing.T) {
diff --git a/src/pkg/runtime/hashmap.goc b/src/pkg/runtime/hashmap.goc
index 36707c6..3327bed 100644
--- a/src/pkg/runtime/hashmap.goc
+++ b/src/pkg/runtime/hashmap.goc
@@ -990,7 +990,7 @@
#pragma textflag NOSPLIT
func reflect·mapdelete(t *MapType, h *Hmap, key *byte) {
if(h == nil)
- runtime·panicstring("delete from nil map");
+ return; // see bug 8051
if(raceenabled) {
runtime·racewritepc(h, runtime·getcallerpc(&t), reflect·mapdelete);
runtime·racereadobjectpc(key, t->key, runtime·getcallerpc(&t), reflect·mapdelete);
