Gabriel Ivăncescu : jscript: Fix Array.reduce when last element doesn't exist.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: ed674d63a4ec07e07a36e0bead84d7ac9bf6c9a7
URL:    https://gitlab.winehq.org/wine/wine/-/commit/ed674d63a4ec07e07a36e0bead84d7a...

Author: Gabriel Ivăncescu <gabrielopcode(a)gmail.com>
Date:   Tue Oct 17 16:18:54 2023 +0300

jscript: Fix Array.reduce when last element doesn't exist.

Signed-off-by: Gabriel Ivăncescu <gabrielopcode(a)gmail.com>

---

 dlls/jscript/array.c     | 4 +++-
 dlls/mshtml/tests/es5.js | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/dlls/jscript/array.c b/dlls/jscript/array.c
index c673b82fed2..36f45120055 100644
--- a/dlls/jscript/array.c
+++ b/dlls/jscript/array.c
@@ -1422,8 +1422,10 @@ static HRESULT Array_reduce(script_ctx_t *ctx, jsval_t vthis, WORD flags, unsign
 
     for(k = 0; k < length; k++) {
         hres = jsdisp_get_idx(jsthis, k, &callback_args[1]);
-        if(hres == DISP_E_UNKNOWNNAME)
+        if(hres == DISP_E_UNKNOWNNAME) {
+            hres = S_OK;
             continue;
+        }
         if(FAILED(hres))
             break;
 
diff --git a/dlls/mshtml/tests/es5.js b/dlls/mshtml/tests/es5.js
index fbcb1b42f3e..b6ce7be3c54 100644
--- a/dlls/mshtml/tests/es5.js
+++ b/dlls/mshtml/tests/es5.js
@@ -1336,6 +1336,9 @@ sync_test("reduce", function() {
     r = [1,2,3].reduce(function(a, value) { return a + value; }, "str");
     ok(r === "str123", "reduce() returned " + r);
 
+    r = [1,2,].reduce(function(a, value) { return a + value; }, "str");
+    ok(r === "str12", "reduce() returned " + r);
+
     array = [1,2,3];
     r = array.reduce(function(a, value, index, src) {
         ok(src === array, "src != array");