Zebediah Figura : jscript: Avoid crash when calling stringify() with no arguments.

[Alexandre Julliard]

Module: wine
Branch: stable
Commit: 91917df545258aceb4eaa6e785ab7b8176b98c94
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=91917df545258aceb4eaa6e785ab7b8176b98c94

Author: Zebediah Figura <z.figura12 at gmail.com>
Date:   Sat May  5 14:13:12 2018 -0500

jscript: Avoid crash when calling stringify() with no arguments.

Signed-off-by: Zebediah Figura <z.figura12 at gmail.com>
Signed-off-by: Jacek Caban <jacek at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>
(cherry picked from commit bf47aebdeeda0ccd16178bf0a52fd0cbd69794fe)
Signed-off-by: Michael Stefaniuc <mstefani at winehq.org>

---

 dlls/jscript/json.c       | 6 ++++++
 dlls/jscript/tests/api.js | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/dlls/jscript/json.c b/dlls/jscript/json.c
index 7d69cf5..0db32cd 100644
--- a/dlls/jscript/json.c
+++ b/dlls/jscript/json.c
@@ -765,6 +765,12 @@ static HRESULT JSON_stringify(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, un
 
     TRACE("\n");
 
+    if(!argc) {
+        if(r)
+            *r = jsval_undefined();
+        return S_OK;
+    }
+
     if(argc >= 2 && is_object_instance(argv[1])) {
         FIXME("Replacer %s not yet supported\n", debugstr_jsval(argv[1]));
         return E_NOTIMPL;
diff --git a/dlls/jscript/tests/api.js b/dlls/jscript/tests/api.js
index 5a78b3a..b825b93 100644
--- a/dlls/jscript/tests/api.js
+++ b/dlls/jscript/tests/api.js
@@ -1807,6 +1807,7 @@ ok(isNaN(tmp), "Math.tan(-Infinity) is not NaN");
         return;
 
     var stringify_tests = [
+        [[], undefined],
         [[true], "true"],
         [[false], "false"],
         [[null], "null"],
@@ -1833,6 +1834,9 @@ ok(isNaN(tmp), "Math.tan(-Infinity) is not NaN");
            "["+i+"] stringify(" + stringify_tests[i][0] + ") returned " + s + " expected " + stringify_tests[i][1]);
     }
 
+    s = JSON.stringify();
+    ok(s === undefined, "stringify() returned " + s + " expected undefined");
+
     s = JSON.stringify(testObj);
     ok(s === undefined || s === "undefined" /* broken on some old versions */,
        "stringify(testObj) returned " + s + " expected undfined");