fix for occasional crashes in icolib

2 files changed, 25 insertions, 5 deletions

diff --git a/src/mir_app/src/IcoLib.h b/src/mir_app/src/IcoLib.h
index 9474295ac1..dd956e2162 100644
--- a/src/mir_app/src/IcoLib.h
+++ b/src/mir_app/src/IcoLib.h
@@ -24,6 +24,8 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 

 #pragma once

 

+#define ICOLIB_MAGIC 0xDEADBEEF

+

 #define SECTIONPARAM_MAKE(index, level, flags) MAKELONG((index)&0xFFFF, MAKEWORD(level, flags))

 #define SECTIONPARAM_INDEX(lparam) LOWORD(lparam)

 #define SECTIONPARAM_LEVEL(lparam) LOBYTE(HIWORD(lparam))

@@ -78,6 +80,7 @@ public:
 struct IcolibItem : public MZeroedObject

 {

 	char*           name;

+	DWORD           signature = ICOLIB_MAGIC;

 	SectionItem*    section;

 	int             orderID;

 	wchar_t*        description;

diff --git a/src/mir_app/src/icolib.cpp b/src/mir_app/src/icolib.cpp
index c5d86d2329..5411646a94 100644
--- a/src/mir_app/src/icolib.cpp
+++ b/src/mir_app/src/icolib.cpp
@@ -72,6 +72,22 @@ void __fastcall SafeDestroyIcon(HICON &hIcon)
 

 // Helper functions to manage Icon resources

 

+static IcolibItem *Handle2Ptr(HANDLE hIcoLib)

+{

+	IcolibItem *p = (IcolibItem *)hIcoLib;

+	if (p == nullptr)

+		return nullptr;

+

+	__try {

+		if (p->signature != ICOLIB_MAGIC)

+			p = nullptr;

+	}

+	__except (EXCEPTION_EXECUTE_HANDLER) {

+		p = nullptr;

+	}

+	return p;

+}

+

 static IconSourceFile* IconSourceFile_Get(const wchar_t *file, bool isPath)

 {

 	if (!file)

@@ -581,9 +597,10 @@ MIR_APP_DLL(void) IcoLib_RemoveIcon(const char *pszIconName)
 

 MIR_APP_DLL(void) IcoLib_RemoveIconByHandle(HANDLE hIcoLib)

 {

-	mir_cslock lck(csIconList);

+	auto *pItem = Handle2Ptr(hIcoLib);

 

-	int i = iconList.getIndex((IcolibItem*)hIcoLib);

+	mir_cslock lck(csIconList);

+	int i = iconList.getIndex(pItem);

 	if (i != -1) {

 		iconList.remove(i);

 		delete iconList[i];

@@ -655,7 +672,7 @@ HICON IconItem_GetDefaultIcon(IcolibItem *item, bool big)
 

 HICON IconItem_GetIcon(HANDLE hIcoLib, bool big)

 {

-	IcolibItem *item = (IcolibItem*)hIcoLib;

+	auto *item = Handle2Ptr(hIcoLib);

 	if (item == nullptr)

 		return nullptr;

 

@@ -724,11 +741,11 @@ MIR_APP_DLL(HANDLE) IcoLib_GetIconHandle(const char *pszIconName)
 

 MIR_APP_DLL(HICON) IcoLib_GetIconByHandle(HANDLE hItem, bool big)

 {

-	if (hItem == nullptr)

+	IcolibItem *pi = Handle2Ptr(hItem);

+	if (pi == nullptr)

 		return nullptr;

 

 	mir_cslock lck(csIconList);

-	IcolibItem *pi = (IcolibItem*)hItem;

 	if (iconList.getIndex(pi) != -1)

 		return IconItem_GetIcon(pi, big);