shell32: Always NULL-terminate path in SHGetPathFromIDList.

dlls/shell32/pidl.c

@@ -1240,8 +1240,7 @@ BOOL WINAPI SHGetPathFromIDListA(LPCITEMIDLIST pidl, LPSTR pszPath)
     BOOL bSuccess;
 
     bSuccess = SHGetPathFromIDListW(pidl, wszPath);
-    if (bSuccess) 
-        WideCharToMultiByte(CP_ACP, 0, wszPath, -1, pszPath, MAX_PATH, NULL, NULL);
+    WideCharToMultiByte(CP_ACP, 0, wszPath, -1, pszPath, MAX_PATH, NULL, NULL);
 
     return bSuccess;
 }
@@ -1262,6 +1261,7 @@ BOOL WINAPI SHGetPathFromIDListW(LPCITEMIDLIST pidl, LPWSTR pszPath)
     TRACE_(shell)("(pidl=%p,%p)\n", pidl, pszPath);
     pdump(pidl);
 
+    *pszPath = '\0';
     if (!pidl)
         return FALSE;
 

dlls/shell32/tests/shlfolder.c

@@ -771,6 +771,13 @@ static void test_SHGetPathFromIDList(void)
 
     if(!pSHGetSpecialFolderPathW) return;
 
+    /* Calling SHGetPathFromIDList with no pidl should return the empty string */
+    wszPath[0] = 'a';
+    wszPath[1] = '\0';
+    result = SHGetPathFromIDListW(NULL, wszPath);
+    ok(!result, "Expected failure\n");
+    ok(!wszPath[0], "Expected empty string\n");
+
     /* Calling SHGetPathFromIDList with an empty pidl should return the desktop folder's path. */
     result = pSHGetSpecialFolderPathW(NULL, wszDesktop, CSIDL_DESKTOP, FALSE);
     ok(result, "SHGetSpecialFolderPathW(CSIDL_DESKTOP) failed! Last error: %08lx\n", GetLastError());
@@ -794,9 +801,12 @@ static void test_SHGetPathFromIDList(void)
     }
 
     SetLastError(0xdeadbeef);
+    wszPath[0] = 'a';
+    wszPath[1] = '\0';
     result = SHGetPathFromIDListW(pidlMyComputer, wszPath);
     ok (!result, "SHGetPathFromIDList succeeded where it shouldn't!\n");
     ok (GetLastError()==0xdeadbeef, "SHGetPathFromIDList shouldn't set last error! Last error: %08lx\n", GetLastError());
+    ok (!wszPath[0], "Expected empty path\n");
     if (result) {
         IShellFolder_Release(psfDesktop);
         return;