jscript: Moved string concatenation to helper function.

dlls/jscript/engine.c

@@ -1447,22 +1447,13 @@ static HRESULT add_eval(script_ctx_t *ctx, jsval_t lval, jsval_t rval, jsval_t *
             hres = to_string(ctx, r, &rstr);
 
         if(SUCCEEDED(hres)) {
-            unsigned len1, len2;
             jsstr_t *ret_str;
 
-            len1 = jsstr_length(lstr);
-            len2 = jsstr_length(rstr);
-
-            ret_str = jsstr_alloc_buf(len1+len2);
-            if(ret_str) {
-                if(len1)
-                    memcpy(ret_str->str, lstr->str, len1*sizeof(WCHAR));
-                if(len2)
-                    memcpy(ret_str->str+len1, rstr->str, len2*sizeof(WCHAR));
+            ret_str = jsstr_concat(lstr, rstr);
+            if(ret_str)
                 *ret = jsval_string(ret_str);
-            }else {
+            else
                 hres = E_OUTOFMEMORY;
-            }
         }
 
         jsstr_release(lstr);

dlls/jscript/jsstr.c

@@ -66,6 +66,25 @@ int jsstr_cmp(jsstr_t *str1, jsstr_t *str2)
     return ret;
 }
 
+jsstr_t *jsstr_concat(jsstr_t *str1, jsstr_t *str2)
+{
+    unsigned len1, len2;
+    jsstr_t *ret;
+
+    len1 = jsstr_length(str1);
+    len2 = jsstr_length(str2);
+
+    ret = jsstr_alloc_buf(len1+len2);
+    if(!ret)
+        return NULL;
+
+    if(len1)
+        memcpy(ret->str, str1->str, len1*sizeof(WCHAR));
+    if(len2)
+        memcpy(ret->str+len1, str2->str, len2*sizeof(WCHAR));
+    return ret;
+}
+
 static jsstr_t *empty_str, *nan_str;
 
 jsstr_t *jsstr_nan(void)

dlls/jscript/jsstr.h

@@ -60,6 +60,7 @@ static inline BOOL jsstr_eq(jsstr_t *str1, jsstr_t *str2)
 }
 
 int jsstr_cmp(jsstr_t*,jsstr_t*) DECLSPEC_HIDDEN;
+jsstr_t *jsstr_concat(jsstr_t*,jsstr_t*) DECLSPEC_HIDDEN;
 
 jsstr_t *jsstr_nan(void) DECLSPEC_HIDDEN;
 jsstr_t *jsstr_empty(void) DECLSPEC_HIDDEN;