From 1a5561c0cf202805436dd58635f6f61b8254d3d3 Mon Sep 17 00:00:00 2001
From: Nikolay Sivov <nsivov@codeweavers.com>
Date: Mon, 5 Jun 2017 02:10:28 +0300
Subject: [PATCH] shell32: Avoid zero length allocations when converting path
 in ExtractIconA() (Valgrind).

Signed-off-by: Nikolay Sivov <nsivov@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
---
 dlls/shell32/shell32_main.c | 15 +++++++--------
 dlls/shell32/shell32_main.h | 15 +++++++++++++++
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/dlls/shell32/shell32_main.c b/dlls/shell32/shell32_main.c
index 04924c0563d..34b906c2fd5 100644
--- a/dlls/shell32/shell32_main.c
+++ b/dlls/shell32/shell32_main.c
@@ -846,17 +846,16 @@ HICON WINAPI DuplicateIcon( HINSTANCE hInstance, HICON hIcon)
 /*************************************************************************
  * ExtractIconA                [SHELL32.@]
  */
-HICON WINAPI ExtractIconA(HINSTANCE hInstance, LPCSTR lpszFile, UINT nIconIndex)
-{   
+HICON WINAPI ExtractIconA(HINSTANCE hInstance, const char *file, UINT nIconIndex)
+{
+    WCHAR *fileW;
     HICON ret;
-    INT len = MultiByteToWideChar(CP_ACP, 0, lpszFile, -1, NULL, 0);
-    LPWSTR lpwstrFile = HeapAlloc(GetProcessHeap(), 0, len * sizeof(WCHAR));
 
-    TRACE("%p %s %d\n", hInstance, lpszFile, nIconIndex);
+    TRACE("%p %s %d\n", hInstance, debugstr_a(file), nIconIndex);
 
-    MultiByteToWideChar(CP_ACP, 0, lpszFile, -1, lpwstrFile, len);
-    ret = ExtractIconW(hInstance, lpwstrFile, nIconIndex);
-    HeapFree(GetProcessHeap(), 0, lpwstrFile);
+    fileW = strdupAtoW(file);
+    ret = ExtractIconW(hInstance, fileW, nIconIndex);
+    HeapFree(GetProcessHeap(), 0, fileW);
 
     return ret;
 }
diff --git a/dlls/shell32/shell32_main.h b/dlls/shell32/shell32_main.h
index 941ca74f321..fc2a5ba8a86 100644
--- a/dlls/shell32/shell32_main.h
+++ b/dlls/shell32/shell32_main.h
@@ -236,4 +236,19 @@ static inline WCHAR *strdupW(const WCHAR *src)
     return dest;
 }
 
+static inline WCHAR *strdupAtoW(const char *str)
+{
+    WCHAR *ret;
+    DWORD len;
+
+    if (!str) return NULL;
+
+    len = MultiByteToWideChar(CP_ACP, 0, str, -1, NULL, 0);
+    ret = HeapAlloc(GetProcessHeap(), 0, len * sizeof(WCHAR));
+    if (ret)
+        MultiByteToWideChar(CP_ACP, 0, str, -1, ret, len);
+
+    return ret;
+}
+
 #endif