1 files changed, 14 insertions, 2 deletions

diff --git a/eval.c b/eval.c
index 2421aea1..57411afc 100644
--- a/eval.c
+++ b/eval.c
@@ -2160,14 +2160,26 @@ post:
 			t1 = force_string(*lhs);
 			t2 = POP_STRING();
 
-			free_wstr(*lhs);
-
 			if (t1 != t2 && t1->valref == 1 && (t1->flags & PERM) == 0) {
 				size_t nlen = t1->stlen + t2->stlen;
 				erealloc(t1->stptr, char *, nlen + 2, "r_interpret");
 				memcpy(t1->stptr + t1->stlen, t2->stptr, t2->stlen);
 				t1->stlen = nlen;
 				t1->stptr[nlen] = '\0';
+
+#if MBS_SUPPORT
+				if ((t1->flags & WSTRCUR) != 0 && (t2->flags & WSTRCUR) != 0) {
+					size_t wlen = t1->wstlen + t2->wstlen;
+
+					erealloc(t1->wstptr, wchar_t *,
+							sizeof(wchar_t) * (wlen + 2), "r_interpret");
+					memcpy(t1->wstptr + t1->wstlen, t2->wstptr, t2->wstlen);
+					t1->wstlen = wlen;
+					t1->wstptr[wlen] = L'\0';
+					t1->flags |= WSTRCUR;
+				} else
+					free_wstr(*lhs);
+#endif
 			} else {
 				size_t nlen = t1->stlen + t2->stlen;  
 				char *p;