jscript: Correctly handle empty matches in String.replace.

dlls/jscript/string.c

@@ -868,6 +868,9 @@ static HRESULT String_replace(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, DI
                 }
                 if(FAILED(hres))
                     break;
+
+                if(!match.len)
+                    cp++;
             }else {
                 match.str = strstrW(cp, match_str);
                 if(!match.str)

dlls/jscript/tests/regexp.js

@@ -583,4 +583,13 @@ ok(i === null, "' undefined '.search() = " + i);
 tmp = "=)".replace(/=/, "?");
 ok(tmp === "?)", "'=)'.replace(/=/, '?') = " + tmp);
 
+tmp = "   ".replace(/^\s*|\s*$/g, "y");
+ok(tmp === "yy", '"   ".replace(/^\s*|\s*$/g, "y") = ' + tmp);
+
+tmp = "xxx".replace(/^\s*|\s*$/g, "");
+ok(tmp === "xxx", '"xxx".replace(/^\s*|\s*$/g, "y") = ' + tmp);
+
+tmp = "xxx".replace(/^\s*|\s*$/g, "y");
+ok(tmp === "yxxxy", '"xxx".replace(/^\s*|\s*$/g, "y") = ' + tmp);
+
 reportSuccess();