Paul Gofman : user32: Put 0 to output string even for 1 char buffer in LoadStringW().

[Alexandre Julliard]

Module: wine
Branch: master
Commit: ad9303d888aa0b463f07f16059ce801d8da10ea2
URL:    https://gitlab.winehq.org/wine/wine/-/commit/ad9303d888aa0b463f07f16059ce801...

Author: Paul Gofman 
Date:   Wed Nov  8 17:56:17 2023 -0600

user32: Put 0 to output string even for 1 char buffer in LoadStringW().

---

dlls/user32/resource.c       | 13 +++----------
 dlls/user32/tests/resource.c |  9 +++++++++
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/dlls/user32/resource.c b/dlls/user32/resource.c
index d2937988765..b050e1eba8c 100644
--- a/dlls/user32/resource.c
+++ b/dlls/user32/resource.c
@@ -185,17 +185,10 @@ INT WINAPI DECLSPEC_HOTPATCH LoadStringW( HINSTANCE instance, UINT resource_id,
     }

i = min(buflen - 1, *p);
-    if (i > 0) {
-	memcpy(buffer, p + 1, i * sizeof (WCHAR));
-        buffer[i] = 0;
-    } else {
-	if (buflen > 1) {
-            buffer[0] = 0;
-	    return 0;
-	}
-    }
+    memcpy(buffer, p + 1, i * sizeof(WCHAR));
+    buffer[i] = 0;

-    TRACE("%s loaded !\n", debugstr_w(buffer));
+    TRACE("returning %s\n", debugstr_w(buffer));
     return i;
 }

diff --git a/dlls/user32/tests/resource.c b/dlls/user32/tests/resource.c
index da4efd2465f..de4bb2c8a53 100644
--- a/dlls/user32/tests/resource.c
+++ b/dlls/user32/tests/resource.c
@@ -147,6 +147,15 @@ static void test_LoadStringW(void)
             "got %lu.\n", GetLastError());
     ok(!returnedstringw[0], "got %#x.\n", returnedstringw[0]);
     ok(returnedstringw[1] == 0xcccc, "got %#x.\n", returnedstringw[1]);
+
+    /* Test short buffer */
+    SetLastError(0xdeadbeef);
+    memset(returnedstringw, 0xcc, sizeof(returnedstringw));
+    length1 = LoadStringW(hInst, 2, returnedstringw, 1); /* get resource string */
+    ok(!length1, "got %d.\n", length1);
+    ok(GetLastError() == 0xdeadbeef, "got %lu.\n", GetLastError());
+    ok(!returnedstringw[0], "got %#x.\n", returnedstringw[0]);
+    ok(returnedstringw[1] == 0xcccc, "got %#x.\n", returnedstringw[1]);
 }

static void test_LoadStringA (void)