From 9c271a637d36c2a9e4f6f369e725f87f2989b9c8 Mon Sep 17 00:00:00 2001
From: Anders <sredna@gmail.com>
Date: Thu, 14 Apr 2022 19:43:45 +0200
Subject: [PATCH] Improve Windows open dialog handling

- Correctly handle OleUninitialize
- Don't leak LPITEMIDLIST if SHGetPathFromIDListW fails
- Use correct nMaxFile size
- Use string alloc helper function
- Hide read-only checkbox
---
 OpenDialog/windows.c | 64 ++++++++++++++++++++++++--------------------
 1 file changed, 35 insertions(+), 29 deletions(-)

diff --git a/OpenDialog/windows.c b/OpenDialog/windows.c
index e711032..edc654a 100644
--- a/OpenDialog/windows.c
+++ b/OpenDialog/windows.c
@@ -2,56 +2,62 @@
 #include <shlobj.h>
 #include "open_dialog.h"
 
+static char *wc_to_utf8_alloc(const wchar_t *wide)
+{
+    unsigned int cb = WideCharToMultiByte(CP_UTF8, 0, wide, -1, NULL, 0, NULL, NULL);
+    if (cb) {
+        char *buffer = (char*) malloc(cb);
+        if (buffer) {
+            WideCharToMultiByte(CP_UTF8, 0, wide, -1, buffer, cb, NULL, NULL);
+            return buffer;
+        }
+    }
+    return NULL;
+}
+
 char *do_open_rom_dialog(void)
 {
     OPENFILENAMEW dialog;
-    static wchar_t filename[MAX_PATH] = {0};
-    
+    wchar_t filename[MAX_PATH];
+
+    filename[0] = '\0';
     memset(&dialog, 0, sizeof(dialog));
     dialog.lStructSize = sizeof(dialog);
     dialog.lpstrFile = filename;
-    dialog.nMaxFile = sizeof(filename);
+    dialog.nMaxFile = MAX_PATH;
     dialog.lpstrFilter = L"Game Boy ROMs\0*.gb;*.gbc;*.sgb;*.isx\0All files\0*.*\0\0";
     dialog.nFilterIndex = 1;
     dialog.lpstrFileTitle = NULL;
     dialog.nMaxFileTitle = 0;
     dialog.lpstrInitialDir = NULL;
-    dialog.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;
-    
-    if (GetOpenFileNameW(&dialog) == TRUE) { 
-        char *ret = malloc(MAX_PATH * 4);
-        WideCharToMultiByte(CP_UTF8, 0, filename, sizeof(filename), ret, MAX_PATH * 4, NULL, NULL);
-        return ret;
+    dialog.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST | OFN_HIDEREADONLY;
+
+    if (GetOpenFileNameW(&dialog) == TRUE) {
+        return wc_to_utf8_alloc(filename);
     }
-    
+
     return NULL;
 }
 
 char *do_open_folder_dialog(void)
 {
-    
+    char *ret = NULL;
     BROWSEINFOW dialog;
-    memset(&dialog, 0, sizeof(dialog));
-    
-    dialog.ulFlags = BIF_USENEWUI;
-    dialog.lpszTitle = L"Select Boot ROMs Folder";
-    
-    OleInitialize(NULL);
-    
-    LPITEMIDLIST list = SHBrowseForFolderW(&dialog);
-    static wchar_t filename[MAX_PATH] = {0};
 
+    memset(&dialog, 0, sizeof(dialog));
+    dialog.ulFlags = BIF_USENEWUI | BIF_RETURNONLYFSDIRS;
+    dialog.lpszTitle = L"Select Boot ROMs Folder";
+
+    HRESULT hrOleInit = OleInitialize(NULL);
+    LPITEMIDLIST list = SHBrowseForFolderW(&dialog);
     if (list) {
-        if (!SHGetPathFromIDListW(list, filename)) {
-            OleUninitialize();
-            return NULL;
+        wchar_t filename[MAX_PATH];
+        if (SHGetPathFromIDListW(list, filename)) {
+            ret = wc_to_utf8_alloc(filename);
         }
-        char *ret = malloc(MAX_PATH * 4);
-        WideCharToMultiByte(CP_UTF8, 0, filename, sizeof(filename), ret, MAX_PATH * 4, NULL, NULL);
         CoTaskMemFree(list);
-        OleUninitialize();
-        return ret;
     }
-    OleUninitialize();
-    return NULL;
+
+    if (SUCCEEDED(hrOleInit)) OleUninitialize();
+    return ret;
 }