[reactos] 01/01: [NTUSER] Plan A: UserDereferenceObject in UserCreateInputContext (#4247)

[Katayama Hirofumi MZ]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=8e8f61989ae86ca0eeb7b…

commit 8e8f61989ae86ca0eeb7b7a50218f1533ae03bf3
Author:     Katayama Hirofumi MZ <katayama.hirofumi.mz(a)gmail.com>
AuthorDate: Wed Jan 5 08:15:32 2022 +0900
Commit:     GitHub <noreply(a)github.com>
CommitDate: Wed Jan 5 08:15:32 2022 +0900

    [NTUSER] Plan A: UserDereferenceObject in UserCreateInputContext (#4247)
    
    - Call UserDereferenceObject function in UserCreateInputContext.
    - Don't call UserDereferenceObject against input context at the other places.
    CORE-11700
---
 win32ss/user/ntuser/main.c    |  6 +-----
 win32ss/user/ntuser/ntstubs.c | 11 +++++++----
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/win32ss/user/ntuser/main.c b/win32ss/user/ntuser/main.c
index fd2eed2aa79..46364a10089 100644
--- a/win32ss/user/ntuser/main.c
+++ b/win32ss/user/ntuser/main.c
@@ -654,11 +654,7 @@ InitThreadCallback(PETHREAD Thread)
     /* Create the default input context */
     if (IS_IMM_MODE())
     {
-        PIMC pIMC = UserCreateInputContext(0);
-        if (pIMC)
-        {
-            UserDereferenceObject(pIMC);
-        }
+        (VOID)UserCreateInputContext(0);
     }
 
     /* Last things to do only if we are not a SYSTEM or CSRSS thread */
diff --git a/win32ss/user/ntuser/ntstubs.c b/win32ss/user/ntuser/ntstubs.c
index 015f8e30650..09b9473756a 100644
--- a/win32ss/user/ntuser/ntstubs.c
+++ b/win32ss/user/ntuser/ntstubs.c
@@ -482,6 +482,9 @@ PIMC FASTCALL UserCreateInputContext(ULONG_PTR dwClientImcData)
     if (!pIMC)
         return NULL;
 
+    // Release the extra reference (UserCreateObject added 2 references).
+    UserDereferenceObject(pIMC);
+
     if (dwClientImcData) // Non-first time.
     {
         // Insert pIMC to the second position (non-default) of the list.
@@ -506,17 +509,17 @@ NtUserCreateInputContext(ULONG_PTR dwClientImcData)
     PIMC pIMC;
     HIMC ret = NULL;
 
+    if (!dwClientImcData)
+        return NULL;
+
     UserEnterExclusive();
 
-    if (!IS_IMM_MODE() || !dwClientImcData)
+    if (!IS_IMM_MODE())
         goto Quit;
 
     pIMC = UserCreateInputContext(dwClientImcData);
     if (pIMC)
-    {
         ret = UserHMGetHandle(pIMC);
-        UserDereferenceObject(pIMC);
-    }
 
 Quit:
     UserLeave();