From a0be2f521d4d2937777a3d5f22491112f1b8eefb Mon Sep 17 00:00:00 2001
From: "trop[bot]" <37223003+trop[bot]@users.noreply.github.com>
Date: Mon, 27 Oct 2025 09:17:27 +0100
Subject: [PATCH] fix: crash on empty dialog extensions array on Windows
 (#48660)

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Shelley Vohr <shelley.vohr@gmail.com>
---
 shell/browser/ui/file_dialog_win.cc | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/shell/browser/ui/file_dialog_win.cc b/shell/browser/ui/file_dialog_win.cc
index 5ded77f646..9a9b218644 100644
--- a/shell/browser/ui/file_dialog_win.cc
+++ b/shell/browser/ui/file_dialog_win.cc
@@ -44,8 +44,7 @@ void ConvertFilters(const Filters& filters,
                     std::vector<std::wstring>* buffer,
                     std::vector<COMDLG_FILTERSPEC>* filterspec) {
   if (filters.empty()) {
-    COMDLG_FILTERSPEC spec = {L"All Files (*.*)", L"*.*"};
-    filterspec->push_back(spec);
+    filterspec->push_back({L"All Files (*.*)", L"*.*"});
     return;
   }
 
@@ -55,11 +54,16 @@ void ConvertFilters(const Filters& filters,
     buffer->push_back(base::UTF8ToWide(filter.first));
     spec.pszName = buffer->back().c_str();
 
-    std::vector<std::string> extensions(filter.second);
-    for (std::string& extension : extensions)
-      extension.insert(0, "*.");
-    buffer->push_back(base::UTF8ToWide(base::JoinString(extensions, ";")));
-    spec.pszSpec = buffer->back().c_str();
+    if (filter.second.empty()) {
+      buffer->push_back(L"*.*");
+      spec.pszSpec = buffer->back().c_str();
+    } else {
+      std::vector<std::string> extensions(filter.second);
+      for (std::string& extension : extensions)
+        extension.insert(0, "*.");
+      buffer->push_back(base::UTF8ToWide(base::JoinString(extensions, ";")));
+      spec.pszSpec = buffer->back().c_str();
+    }
 
     filterspec->push_back(spec);
   }