4 files changed, 79 insertions, 3 deletions

diff --git a/src/lib/font.h b/src/lib/font.h
index b9e90f65e..0afd873e1 100644
--- a/src/lib/font.h
+++ b/src/lib/font.h
@@ -85,6 +85,10 @@ public:
 		boost::optional<boost::filesystem::path> file;
 	};
 
+	Content content() const {
+		return _content;
+	}
+
 	boost::signals2::signal<void()> Changed;
 
 private:
diff --git a/src/lib/font_comparator.h b/src/lib/font_comparator.h
new file mode 100644
index 000000000..07ad15b6a
--- /dev/null
+++ b/src/lib/font_comparator.h
@@ -0,0 +1,68 @@
+/*
+    Copyright (C) 2023 Carl Hetherington <cth@carlh.net>
+
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    DCP-o-matic is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "dcpomatic_assert.h"
+
+
+/** Comparator to allow dcpomatic::Font::Content to be compared for use in a map */
+struct FontComparator
+{
+	bool operator()(dcpomatic::Font::Content const& a, dcpomatic::Font::Content const& b) const {
+		auto const a_has_file = static_cast<bool>(a.file);
+		auto const b_has_file = static_cast<bool>(b.file);
+		auto const a_has_data = static_cast<bool>(a.data);
+		auto const b_has_data = static_cast<bool>(b.data);
+
+		if (!a_has_file && !a_has_data && !b_has_file && !b_has_data) {
+			/* Neither font has any font data: a == b */
+			return false;
+		} else if (!a_has_file && !a_has_data) {
+			/* Fonts with no data are the "lowest": a < b */
+			return true;
+		} else if (!b_has_file && !b_has_data) {
+			/* ... so here b < a */
+			return false;
+		} else if (a_has_file && !b_has_file) {
+			/* Fonts with file are lower than fonts with data: a < b */
+			return true;
+		} else if (!a_has_file && b_has_file) {
+			/* ... so here b < a */
+			return false;
+		} else if (a_has_file && b_has_file) {
+			/* Compared as "equals" */
+			return a.file->string() < b.file->string();
+		} else if (a_has_data && b_has_data) {
+			/* Compared as "equals" */
+			auto const a_size = a.data->size();
+			auto const b_size = b.data->size();
+			if (a_size != b_size) {
+				return a_size < b_size;
+			}
+			return memcmp(a.data->data(), b.data->data(), a_size) < 0;
+		}
+
+		/* Should never get here */
+		DCPOMATIC_ASSERT(false);
+		return false;
+	};
+};
+
+
diff --git a/src/lib/font_config.cc b/src/lib/font_config.cc
index d4a442fc1..8804bd6d9 100644
--- a/src/lib/font_config.cc
+++ b/src/lib/font_config.cc
@@ -56,7 +56,7 @@ FontConfig::~FontConfig()
 string
 FontConfig::make_font_available(shared_ptr<dcpomatic::Font> font)
 {
-	auto existing = _available_fonts.find(font->id());
+	auto existing = _available_fonts.find(font->content());
 	if (existing != _available_fonts.end()) {
 		return existing->second;
 	}
@@ -107,7 +107,10 @@ FontConfig::make_font_available(shared_ptr<dcpomatic::Font> font)
 
 	DCPOMATIC_ASSERT(font_name);
 
-	_available_fonts[font->id()] = *font_name;
+	/* We need to use the font object as the key, as we may be passed the same shared_ptr to a modified
+	 * Font object in the future and in that case we need to load the new font.
+	 */
+	_available_fonts[font->content()] = *font_name;
 
 	FcConfigBuildFonts(_config);
 	return *font_name;
diff --git a/src/lib/font_config.h b/src/lib/font_config.h
index edcb4be36..57f733b7b 100644
--- a/src/lib/font_config.h
+++ b/src/lib/font_config.h
@@ -19,6 +19,7 @@
 */
 
 
+#include "font_comparator.h"
 #include <fontconfig/fontconfig.h>
 #include <boost/filesystem.hpp>
 #include <map>
@@ -41,7 +42,7 @@ private:
 	~FontConfig();
 
 	FcConfig* _config = nullptr;
-	std::map<std::string, std::string> _available_fonts;
+	std::map<dcpomatic::Font::Content, std::string, FontComparator> _available_fonts;
 
 	std::vector<boost::filesystem::path> _temp_files;