Alexandre Julliard : server: Fix returned error when creating an existing symlink.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: afb16d3ee2cdbc5c7fc6119fa9c805ca0611baa6
URL:    https://gitlab.winehq.org/wine/wine/-/commit/afb16d3ee2cdbc5c7fc6119fa9c805c...

Author: Alexandre Julliard <julliard(a)winehq.org>
Date:   Mon Oct 30 13:32:46 2023 +0100

server: Fix returned error when creating an existing symlink.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55839

---

 dlls/ntdll/tests/om.c | 20 ++++++++++++++++++--
 server/symlink.c      | 15 ++++++++++-----
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/dlls/ntdll/tests/om.c b/dlls/ntdll/tests/om.c
index b612a0844a4..62659fc8cb4 100644
--- a/dlls/ntdll/tests/om.c
+++ b/dlls/ntdll/tests/om.c
@@ -1408,9 +1408,15 @@ static void test_symboliclink(void)
     pNtClose(link);
 
     RtlInitUnicodeString(&str, L"\\");
+    attr.Attributes = OBJ_OPENIF;
     status = pNtCreateSymbolicLinkObject(&h, SYMBOLIC_LINK_QUERY, &attr, &target);
-    todo_wine ok(status == STATUS_OBJECT_TYPE_MISMATCH,
-                 "NtCreateSymbolicLinkObject should have failed with STATUS_OBJECT_TYPE_MISMATCH got(%08lx)\n", status);
+    ok(status == STATUS_OBJECT_TYPE_MISMATCH,
+       "NtCreateSymbolicLinkObject should have failed with STATUS_OBJECT_TYPE_MISMATCH got(%08lx)\n", status);
+    attr.Attributes = 0;
+    status = pNtCreateSymbolicLinkObject(&h, SYMBOLIC_LINK_QUERY, &attr, &target);
+    todo_wine
+    ok(status == STATUS_OBJECT_TYPE_MISMATCH,
+       "NtCreateSymbolicLinkObject should have failed with STATUS_OBJECT_TYPE_MISMATCH got(%08lx)\n", status);
 
     RtlInitUnicodeString( &target, L"->Somewhere");
 
@@ -1480,6 +1486,16 @@ static void test_symboliclink(void)
     ok(status == STATUS_SUCCESS, "Got unexpected status %#lx.\n", status);
     pNtClose(h);
 
+    attr.Attributes = OBJ_OPENIF;
+    status = pNtCreateSymbolicLinkObject( &h, SYMBOLIC_LINK_QUERY, &attr, &target );
+    ok(status == STATUS_SUCCESS || broken( status == STATUS_OBJECT_NAME_EXISTS ), /* <= win10 1507 */
+       "Got unexpected status %#lx.\n", status);
+    pNtClose(h);
+    attr.Attributes = 0;
+    status = pNtCreateSymbolicLinkObject( &h, SYMBOLIC_LINK_QUERY, &attr, &target );
+    ok(status == STATUS_OBJECT_NAME_COLLISION, "Got unexpected status %#lx.\n", status);
+    pNtClose(h);
+
     InitializeObjectAttributes(&attr, &str, 0, 0, NULL);
     RtlInitUnicodeString( &str, L"\\BaseNamedObjects\\om.c-test\\" );
     status = NtCreateFile(&h, GENERIC_READ | SYNCHRONIZE, &attr, &iosb, NULL, 0,
diff --git a/server/symlink.c b/server/symlink.c
index 27d48e2f994..dd28efd3a75 100644
--- a/server/symlink.c
+++ b/server/symlink.c
@@ -155,13 +155,18 @@ struct object *create_symlink( struct object *root, const struct unicode_str *na
         set_error( STATUS_INVALID_PARAMETER );
         return NULL;
     }
-    if (!(symlink = create_named_object( root, &symlink_ops, name, attr, sd ))) return NULL;
-    if (get_error() != STATUS_OBJECT_NAME_EXISTS && !(symlink->target = memdup( target->str, target->len )))
+    if (!(symlink = create_named_object( root, &symlink_ops, name, attr | OBJ_OPENLINK, sd ))) return NULL;
+    if (get_error() != STATUS_OBJECT_NAME_EXISTS)
     {
-        release_object( symlink );
-        return NULL;
+        symlink->len = target->len;
+        if (!(symlink->target = memdup( target->str, target->len )))
+        {
+            release_object( symlink );
+            return NULL;
+        }
     }
-    symlink->len = target->len;
+    else clear_error();
+
     return &symlink->obj;
 }