Jacek Caban : jscript: Properly handle NULL strings in add_eval.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: f8b20563aa5c8419e82020698295d27e6aab5688
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=f8b20563aa5c8419e820206982...

Author: Jacek Caban 
Date:   Thu Mar  8 14:28:02 2012 +0100

jscript: Properly handle NULL strings in add_eval.

---

dlls/jscript/engine.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/dlls/jscript/engine.c b/dlls/jscript/engine.c
index 11b434f..0ae142a 100644
--- a/dlls/jscript/engine.c
+++ b/dlls/jscript/engine.c
@@ -1509,8 +1509,11 @@ static HRESULT add_eval(script_ctx_t *ctx, VARIANT *lval, VARIANT *rval, jsexcep

V_VT(retv) = VT_BSTR;
             V_BSTR(retv) = SysAllocStringLen(NULL, len1+len2);
-            memcpy(V_BSTR(retv), lstr, len1*sizeof(WCHAR));
-            memcpy(V_BSTR(retv)+len1, rstr, (len2+1)*sizeof(WCHAR));
+            if(len1)
+                memcpy(V_BSTR(retv), lstr, len1*sizeof(WCHAR));
+            if(len2)
+                memcpy(V_BSTR(retv)+len1, rstr, len2*sizeof(WCHAR));
+            V_BSTR(retv)[len1+len2] = 0;
         }

if(V_VT(&l) != VT_BSTR)