From 89da4f3b8ccf513e94a3887e68eef4a95d2a6be2 Mon Sep 17 00:00:00 2001
From: Struma <strix@struma.me>
Date: Sun, 19 Apr 2020 06:44:41 -0400
Subject: [PATCH] Bind checking case insensitive filenames from Ruby

---
 binding/filesystem-binding.cpp | 12 ++++++++++++
 src/filesystem.h               |  3 +++
 src/filesystem.mm              | 12 ++++++++++--
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/binding/filesystem-binding.cpp b/binding/filesystem-binding.cpp
index a58b8c27..4e8765d2 100644
--- a/binding/filesystem-binding.cpp
+++ b/binding/filesystem-binding.cpp
@@ -250,6 +250,17 @@ RB_METHOD(_marshalLoad) {
 }
 #endif
 
+RB_METHOD(fileIntDesensitize) {
+  RB_UNUSED_PARAM;
+
+  VALUE filename;
+  rb_scan_args(argc, argv, "1", &filename);
+  SafeStringValue(filename);
+
+  return rb_str_new_cstr(
+      shState->fileSystem().desensitize(RSTRING_PTR(filename)));
+}
+
 void fileIntBindingInit() {
   VALUE klass = rb_define_class("FileInt", rb_cIO);
 #if RAPI_FULL > 187
@@ -269,6 +280,7 @@ void fileIntBindingInit() {
 #endif
   _rb_define_method(klass, "binmode", fileIntBinmode);
   _rb_define_method(klass, "close", fileIntClose);
+  rb_define_singleton_method(klass, "desensitize", RUBY_METHOD_FUNC(fileIntDesensitize), -1);
 
   _rb_define_module_function(rb_mKernel, "load_data", kernelLoadData);
   _rb_define_module_function(rb_mKernel, "save_data", kernelSaveData);
diff --git a/src/filesystem.h b/src/filesystem.h
index d78c84a6..76781e74 100644
--- a/src/filesystem.h
+++ b/src/filesystem.h
@@ -23,6 +23,7 @@
 #define FILESYSTEM_H
 
 #include <SDL_rwops.h>
+#include <string>
 
 struct FileSystemPrivate;
 class SharedFontState;
@@ -69,6 +70,8 @@ public:
 	/* Does not perform extension supplementing */
 	bool exists(const char *filename);
 
+	const char *desensitize(const char *filename);
+
 private:
 	FileSystemPrivate *p;
 };
diff --git a/src/filesystem.mm b/src/filesystem.mm
index 04b7933c..0eaadbe6 100644
--- a/src/filesystem.mm
+++ b/src/filesystem.mm
@@ -622,10 +622,11 @@ void FileSystem::openRead(OpenHandler &handler, const char *filename) {
     throw Exception(Exception::NoFileError, "%s", filename);
 }
 
-// FIXME: This is (a) slower than RGSS and (b) case-sensitive
+// FIXME: This is slower than RGSS
 void FileSystem::openReadRaw(SDL_RWops &ops, const char *filename,
                              bool freeOnClose) {
-  PHYSFS_File *handle = PHYSFS_openRead(filename);
+
+  PHYSFS_File *handle = PHYSFS_openRead(desensitize(filename));
 
   // assert(handle);
   if (!handle)
@@ -669,3 +670,10 @@ char *FileSystem::normalize(const char *pathname, bool preferred,
 bool FileSystem::exists(const char *filename) {
   return PHYSFS_exists(filename);
 }
+
+const char *FileSystem::desensitize(const char *filename) {
+  OFString *fn_lower = @(filename).lowercaseString;
+  if (p->havePathCache && p->pathCache.contains(fn_lower.UTF8String))
+    return p->pathCache[fn_lower.UTF8String].c_str();
+  return filename;
+}