[PATCH 4/4] uxtheme: Reference count theme classes.

[Zhiyi Zhang]

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=29974
Signed-off-by: Zhiyi Zhang <zzhang at codeweavers.com>
---
 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 d834c9604b9..8377ca9ebce 100644
--- a/dlls/uxtheme/msstyles.c
+++ b/dlls/uxtheme/msstyles.c
@@ -446,6 +446,7 @@ 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);
@@ -1030,6 +1031,7 @@ 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;
@@ -1049,6 +1051,8 @@ PTHEME_CLASS MSSTYLES_OpenThemeClass(LPCWSTR pszAppName, LPCWSTR pszClassList, U
  */
 HRESULT MSSTYLES_CloseThemeClass(PTHEME_CLASS tc)
 {
+    LONG refcount;
+
     __TRY
     {
         if (tc->signature != THEME_CLASS_SIGNATURE)
@@ -1066,7 +1070,10 @@ 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 89937227ee2..8db0aa4c03c 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];
-- 
2.32.0