From ed1caccac78b1bdf2ff8262853d25eb7a61f5062 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 11 Dec 2015 11:16:09 +0530
Subject: [PATCH] Fix bundled Universal CRT not working on computers where the
 Universal CRT was not already installed

---
 setup/installer/windows/freeze.py | 19 +++++++++++--------
 setup/installer/windows/main.c    |  2 ++
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/setup/installer/windows/freeze.py b/setup/installer/windows/freeze.py
index b20d2892e5..6983e0ffa4 100644
--- a/setup/installer/windows/freeze.py
+++ b/setup/installer/windows/freeze.py
@@ -730,14 +730,17 @@ class Win32Freeze(Command, WixMixIn):
         vc_path = os.path.join(r'C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\redist', plat, 'Microsoft.VC140.CRT')
         if not os.path.exists(vc_path):
             raise SystemExit('Visual Studio redistributable CRT not found')
-        # I cannot get app local deployment of the UCRT to work. Things left to
-        # try: try dlls from the windows sdk standalone, try manually loading
-        # ucrtbase.dll and some api dlls before loading the launcher.
-        # sdk_path = os.path.join(r'C:\Program Files (x86)\Windows Kits\10\Redist\ucrt\DLLs', plat)
-        # if not os.path.exists(sdk_path):
-        #     raise SystemExit('Windows 10 redistributable CRT not found')
-        # for dll in glob.glob(os.path.join(sdk_path, '*.dll')):
-        #     shutil.copy2(dll, self.dll_dir)
+        # We cannot use the Universal CRT DLLs that come with Visual Studio, as
+        # they are broken. Have to use the ones from the Standalone SDK for Windows 10.
+        # However, I dont want to install this SDK, incase it messes things up,
+        # so the below path points to dlls I got from installing the SDK in a
+        # different VM. To re-create just copy the api-ms*.dll and ucrtbase.dll
+        # files from a previous calibre install.
+        sdk_path = os.path.join(SW, '..', 'ucrt', 'DLLs', plat)
+        if not os.path.exists(sdk_path):
+            raise SystemExit('Windows 10 Universal CRT redistributable not found')
+        for dll in glob.glob(os.path.join(sdk_path, '*.dll')):
+            shutil.copy2(dll, self.dll_dir)
         for dll in glob.glob(os.path.join(vc_path, '*.dll')):
             bname = os.path.basename(dll)
             if not bname.startswith('vccorlib') and not bname.startswith('concrt'):
diff --git a/setup/installer/windows/main.c b/setup/installer/windows/main.c
index 126cffb823..7d9d4fe5f0 100644
--- a/setup/installer/windows/main.c
+++ b/setup/installer/windows/main.c
@@ -78,6 +78,8 @@ static ENTRYPROC load_launcher_dll() {
         show_last_error(L"Failed to set DLL directory");
         return NULL;
     }
+    // Have to load ucrtbase manually first, otherwise loading fails on systems where the
+    // Universal CRT is not installed.
     if (!LoadLibraryW(L"ucrtbase.dll")) {
         show_last_error(L"Unable to find ucrtbase.dll. You should install all Windows updates on your computer to get this file.");
         return NULL;