Zhiyi Zhang : uxtheme: Reference count theme classes.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 113eca095a33693c18323275c7bd420888914837
URL:    https://gitlab.winehq.org/wine/wine/-/commit/113eca095a33693c18323275c7bd420...

Author: Zhiyi Zhang 
Date:   Fri Aug 12 11:32:54 2022 +0800

uxtheme: Reference count theme classes.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=29974
Signed-off-by: Zhiyi Zhang

---

dlls/uxtheme/msstyles.c | 9 ++++++++-
 dlls/uxtheme/msstyles.h | 1 +
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/dlls/uxtheme/msstyles.c b/dlls/uxtheme/msstyles.c
index d871f213b05..529a280b2e5 100644
--- a/dlls/uxtheme/msstyles.c
+++ b/dlls/uxtheme/msstyles.c
@@ -447,6 +447,7 @@ static PTHEME_CLASS MSSTYLES_AddClass(PTHEME_FILE tf, LPCWSTR pszAppName, LPCWST

cur = heap_alloc(sizeof(*cur));
     cur->signature = THEME_CLASS_SIGNATURE;
+    cur->refcount = 0;
     cur->hTheme = tf->hTheme;
     lstrcpyW(cur->szAppName, pszAppName);
     lstrcpyW(cur->szClassName, pszClassName);
@@ -1061,6 +1062,7 @@ PTHEME_CLASS MSSTYLES_OpenThemeClass(LPCWSTR pszAppName, LPCWSTR pszClassList, U
         TRACE("Opened app %s, class %s from list %s\n", debugstr_w(cls->szAppName), debugstr_w(cls->szClassName), debugstr_w(pszClassList));
    cls->tf = tfActiveTheme;
    cls->tf->dwRefCount++;
+        InterlockedIncrement(&cls->refcount);
         cls->dpi = dpi;
     }
     return cls;
@@ -1080,6 +1082,8 @@ PTHEME_CLASS MSSTYLES_OpenThemeClass(LPCWSTR pszAppName, LPCWSTR pszClassList, U
  */
 HRESULT MSSTYLES_CloseThemeClass(PTHEME_CLASS tc)
 {
+    LONG refcount;
+
     __TRY
     {
         if (tc->signature != THEME_CLASS_SIGNATURE)
@@ -1097,7 +1101,10 @@ HRESULT MSSTYLES_CloseThemeClass(PTHEME_CLASS tc)
         return E_HANDLE;
     }

-    MSSTYLES_CloseThemeFile (tc->tf);
+    refcount = InterlockedDecrement(&tc->refcount);
+    /* Some buggy apps may double free HTHEME handles */
+    if (refcount >= 0)
+        MSSTYLES_CloseThemeFile(tc->tf);
     return S_OK;
 }

diff --git a/dlls/uxtheme/msstyles.h b/dlls/uxtheme/msstyles.h
index a1918314341..9fe99784838 100644
--- a/dlls/uxtheme/msstyles.h
+++ b/dlls/uxtheme/msstyles.h
@@ -50,6 +50,7 @@ struct _THEME_FILE;

typedef struct _THEME_CLASS {
     DWORD signature;
+    LONG refcount;
     HMODULE hTheme;
     struct _THEME_FILE* tf;
     WCHAR szAppName[MAX_THEME_APP_NAME];