[PATCH 0/1] MR2324: advapi32/tests: Fix the RegEnumValueA() tests in UTF-8 locales.

[Francois Gouget (＠fgouget)]

On Windows RegEnumValueA() is buggy such that when the value name
buffer is too small, it may way overestimate the required data buffer
size, sometimes returning more than the sufficiently large buffer it was
provided, in which case that buffer is untouched and thus not
NUL-terminated.
So modify the tests to accept this broken result and avoid checking
out-of-bounds data.

Wine-Bug: https://bugs.winehq.org//show_bug.cgi?id=53172

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/2324

[PATCH 1/1] advapi32/tests: Fix the RegEnumValueA() tests in UTF-8 locales.

[Francois Gouget]

From: Francois Gouget <fgouget(a)codeweavers.com>

On Windows RegEnumValueA() is buggy such that when the value name
buffer is too small, it may way overestimate the required data buffer
size, sometimes returning more than the sufficiently large buffer it was
provided, in which case that buffer is untouched and thus not
NUL-terminated.
So modify the tests to accept this broken result and avoid checking
out-of-bounds data.

Wine-Bug: https://bugs.winehq.org//show_bug.cgi?id=53172
---
 dlls/advapi32/tests/registry.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/dlls/advapi32/tests/registry.c b/dlls/advapi32/tests/registry.c
index 480e96ef6ee..524c3e0ef76 100644
--- a/dlls/advapi32/tests/registry.c
+++ b/dlls/advapi32/tests/registry.c
@@ -476,7 +476,7 @@ static void test_enum_value(void)
 {
     DWORD res;
     HKEY test_key;
-    char value[20], data[20];
+    char value[20], data[30];
     WCHAR valueW[20], dataW[20];
     DWORD val_count, data_count, type;
 
@@ -542,39 +542,50 @@ static void test_enum_value(void)
 
     /* overflow name */
     val_count = 3;
-    data_count = 20;
+    data_count = 16;
     type = 1234;
     strcpy( value, "xxxxxxxxxx" );
     memset( data, 'x', sizeof(data) );
+    data[sizeof(data)-1] = '\0';
     res = RegEnumValueA( test_key, 0, value, &val_count, NULL, &type, (LPBYTE)data, &data_count );
     ok( res == ERROR_MORE_DATA, "expected ERROR_MORE_DATA, got %ld\n", res );
     ok( val_count == 3, "val_count set to %ld\n", val_count );
-    /* Chinese, Japanese, and Korean editions of Windows 10 sometimes set data_count to a higher value */
+    /* In double-byte and UTF-8 locales Windows 10 may set data_count > 7,
+     * potentially even more than the declared buffer size, in which case the
+     * buffer is not NUL-terminated.
+     */
     ok( data_count == 7 || broken( data_count > 7 ), "data_count set to %ld instead of 7\n", data_count );
     ok( type == REG_SZ, "type %ld is not REG_SZ\n", type );
-    /* v5.1.2600.0 (XP Home and Professional) does not touch value or data in this case */
+    /* v5.1.2600.0 (XP Home and Professional) does not touch value or data in
+     * this case. Neither does Windows 10 21H1 in UTF-8 locales.
+     */
     ok( !strcmp( value, "Te" ) || !strcmp( value, "xxxxxxxxxx" ), 
         "value set to '%s' instead of 'Te' or 'xxxxxxxxxx'\n", value );
     ok( !strcmp( data, "foobar" ) || !strcmp( data, "xxxxxxx" ) ||
-        broken( data_count > 7 && strspn( data, "x" ) == data_count && data[data_count] == 0 ),
+        broken( data_count > 7 && data_count < 16 &&
+                strspn( data, "x" ) == data_count && data[data_count] == 0 ) ||
+        broken( data_count >= 16 && strspn( data, "x" ) == sizeof(data) - 1 ),
         "data set to '%s' instead of 'foobar' or x's, data_count=%lu\n", data, data_count );
 
     /* overflow empty name */
     val_count = 0;
-    data_count = 20;
+    data_count = 16;
     type = 1234;
     strcpy( value, "xxxxxxxxxx" );
     memset( data, 'x', sizeof(data) );
+    data[sizeof(data)-1] = '\0';
     res = RegEnumValueA( test_key, 0, value, &val_count, NULL, &type, (LPBYTE)data, &data_count );
     ok( res == ERROR_MORE_DATA, "expected ERROR_MORE_DATA, got %ld\n", res );
     ok( val_count == 0, "val_count set to %ld\n", val_count );
-    /* Chinese, Japanese, and Korean editions of Windows 10 sometimes set data_count to a higher value */
+    /* See comment in 'overflow name' section */
     ok( data_count == 7 || broken( data_count > 7 ), "data_count set to %ld instead of 7\n", data_count );
     ok( type == REG_SZ, "type %ld is not REG_SZ\n", type );
     ok( !strcmp( value, "xxxxxxxxxx" ), "value set to '%s'\n", value );
-    /* v5.1.2600.0 (XP Home and Professional) does not touch data in this case */
+    /* See comment in 'overflow name' section */
     ok( !strcmp( data, "foobar" ) || !strcmp( data, "xxxxxxx" ) ||
-        broken( data_count > 7 && strspn( data, "x" ) == data_count && data[data_count] == 0 ),
+        broken( data_count > 7 && data_count < 16 &&
+                strspn( data, "x" ) == data_count && data[data_count] == 0 ) ||
+        broken( data_count >= 16 && strspn( data, "x" ) == sizeof(data) - 1 ),
         "data set to '%s' instead of 'foobar' or x's, data_count=%lu\n", data, data_count );
 
     /* overflow data */
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/2324