Fix DCP content font ID allocation to cope with DCPs that have multiple fonts

with the same name in the same reel (#2600).

Previously we had this id_for_font_in_reel() which would give an ID
of N_font-ID.  This means we got duplicate font IDs.

Here we replace that method with FontAllocator, which gives an ID of
N_font-ID for the first font and M_font-ID, where M is a number higher than
the highest reel index.  The idea is to support the required new IDs
without breaking exisiting projects.

There is some documentation of how it works  in doc/design/fonts

6 files changed, 123 insertions, 62 deletions

diff --git a/test/data b/test/data
-Subproject c0f7e2c3f702b469db8e146eb9e650f9998d18a
+Subproject c40dcfabfccce346822a662012fa86814206d6a
diff --git a/test/font_id_allocator_test.cc b/test/font_id_allocator_test.cc
new file mode 100644
index 000000000..7c93c6b78
--- /dev/null
+++ b/test/font_id_allocator_test.cc
@@ -0,0 +1,72 @@
+/*
+    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 "lib/font_id_allocator.h"
+#include <boost/test/unit_test.hpp>
+
+
+BOOST_AUTO_TEST_CASE(font_id_allocator_test_without_disambiguation)
+{
+	FontIDAllocator allocator;
+
+	/* Reel 0 has just one asset with two fonts */
+	allocator.add_font(0, "asset1", "font");
+	allocator.add_font(0, "asset1", "font2");
+
+	/* Reel 1 has two assets each with two more fonts */
+	allocator.add_font(1, "asset2", "font");
+	allocator.add_font(1, "asset2", "font2");
+	allocator.add_font(1, "asset3", "font3");
+	allocator.add_font(1, "asset3", "font4");
+
+	allocator.allocate();
+
+	BOOST_CHECK(allocator.font_id(0, "asset1", "font") == "0_font");
+	BOOST_CHECK(allocator.font_id(0, "asset1", "font2") == "0_font2");
+	BOOST_CHECK(allocator.font_id(1, "asset2", "font") == "1_font");
+	BOOST_CHECK(allocator.font_id(1, "asset2", "font2") == "1_font2");
+	BOOST_CHECK(allocator.font_id(1, "asset3", "font3") == "1_font3");
+	BOOST_CHECK(allocator.font_id(1, "asset3", "font4") == "1_font4");
+}
+
+
+BOOST_AUTO_TEST_CASE(font_id_allocator_test_with_disambiguation)
+{
+	FontIDAllocator allocator;
+
+	/* Reel 0 has two assets each with a font with the same ID (perhaps a subtitle and a ccap).
+	 * This would have crashed DCP-o-matic before the FontIDAllocator change (bug #2600)
+	 * so it's OK if the second font gets a new index that we didn't see before.
+	 */
+	allocator.add_font(0, "asset1", "font");
+	allocator.add_font(0, "asset2", "font");
+
+	/* Reel 1 has one asset with another font */
+	allocator.add_font(1, "asset3", "font1");
+
+	allocator.allocate();
+
+	BOOST_CHECK(allocator.font_id(0, "asset1", "font") == "0_font");
+	/* This should get a prefix that is higher than any reel index */
+	BOOST_CHECK(allocator.font_id(0, "asset2", "font") == "2_font");
+	BOOST_CHECK(allocator.font_id(1, "asset3", "font1") == "1_font1");
+}
+
diff --git a/test/hints_test.cc b/test/hints_test.cc
index 0e856c4f9..a989d3aeb 100644
--- a/test/hints_test.cc
+++ b/test/hints_test.cc
@@ -193,12 +193,13 @@ BOOST_AUTO_TEST_CASE (hint_subtitle_mxf_too_big)
 		}
 		fake_font.close();
 
-		auto content = content_factory("test/data/" + name + ".srt")[0];
+		auto content = content_factory(String::compose("test/data/%1%2.xml", name, i))[0];
 		content->text[0]->set_type(TextType::OPEN_SUBTITLE);
 		content->text[0]->set_language(dcp::LanguageTag("en-US"));
 		film->examine_and_add_content(content);
 		BOOST_REQUIRE (!wait_for_jobs());
-		content->text[0]->get_font("")->set_file("build/test/hint_subtitle_mxf_too_big.ttf");
+		auto const font = content->text[0]->get_font(String::compose("font_%1", i));
+		font->set_file("build/test/hint_subtitle_mxf_too_big.ttf");
 	}
 
 	auto hints = get_hints (film);
diff --git a/test/vf_test.cc b/test/vf_test.cc
index ecd615d98..249f9c5b0 100644
--- a/test/vf_test.cc
+++ b/test/vf_test.cc
@@ -28,8 +28,11 @@
 #include "lib/content_factory.h"
 #include "lib/dcp_content.h"
 #include "lib/dcp_content_type.h"
+#include "lib/examine_content_job.h"
 #include "lib/ffmpeg_content.h"
 #include "lib/film.h"
+#include "lib/job_manager.h"
+#include "lib/make_dcp.h"
 #include "lib/player.h"
 #include "lib/text_content.h"
 #include "lib/referenced_reel_asset.h"
@@ -423,3 +426,47 @@ BOOST_AUTO_TEST_CASE(test_referencing_ov_with_subs_when_adding_ccaps)
 	std::cout << why_not << "\n";
 }
 
+
+BOOST_AUTO_TEST_CASE(test_duplicate_font_id_in_vf)
+{
+	string const name("test_duplicate_font_id_in_vf");
+	auto subs = content_factory("test/data/15s.srt");
+	auto ov = new_test_film2(name + "_ov", subs);
+	make_and_verify_dcp(
+		ov,
+		{
+			dcp::VerificationNote::Code::MISSING_SUBTITLE_LANGUAGE,
+			dcp::VerificationNote::Code::INVALID_SUBTITLE_FIRST_TEXT_TIME,
+			dcp::VerificationNote::Code::MISSING_CPL_METADATA
+		});
+
+	auto ccaps = content_factory("test/data/15s.srt")[0];
+	auto ov_dcp = make_shared<DCPContent>(ov->dir(ov->dcp_name(false)));
+	auto vf = new_test_film2(name + "_vf", { ov_dcp, ccaps });
+	ov_dcp->set_reference_audio(true);
+	ov_dcp->set_reference_video(true);
+	ov_dcp->text[0]->set_use(true);
+	ccaps->text[0]->set_type(TextType::CLOSED_CAPTION);
+	string why_not;
+	BOOST_CHECK_MESSAGE(ov_dcp->can_reference_text(vf, TextType::OPEN_SUBTITLE, why_not), why_not);
+	ov_dcp->set_reference_text(TextType::OPEN_SUBTITLE, true);
+	vf->write_metadata();
+	make_dcp(vf, TranscodeJob::ChangedBehaviour::IGNORE);
+	BOOST_REQUIRE(!wait_for_jobs());
+
+	auto vf_dcp = make_shared<DCPContent>(vf->dir(vf->dcp_name(false)));
+
+	auto test = new_test_film2(name + "_test", { vf_dcp });
+	vf_dcp->add_ov(ov->dir(ov->dcp_name(false)));
+	JobManager::instance()->add(make_shared<ExamineContentJob>(test, vf_dcp));
+	BOOST_CHECK(!wait_for_jobs());
+
+	make_and_verify_dcp(
+		test,
+		{
+			dcp::VerificationNote::Code::MISSING_SUBTITLE_LANGUAGE,
+			dcp::VerificationNote::Code::INVALID_SUBTITLE_FIRST_TEXT_TIME,
+			dcp::VerificationNote::Code::MISSING_CPL_METADATA,
+		});
+}
+
diff --git a/test/writer_test.cc b/test/writer_test.cc
index d5cafe1fb..7b2a2db00 100644
--- a/test/writer_test.cc
+++ b/test/writer_test.cc
@@ -101,63 +101,3 @@ BOOST_AUTO_TEST_CASE (interrupt_writer)
 	dcpomatic_sleep_seconds (1);
 	cl.run ();
 }
-
-
-BOOST_AUTO_TEST_CASE (writer_disambiguate_font_ids1)
-{
-	auto film = new_test_film2("writer_disambiguate_font_ids1", {});
-	Writer writer(film, {});
-
-	auto fonts = vector<shared_ptr<dcpomatic::Font>> {
-		make_shared<dcpomatic::Font>("a"),
-		make_shared<dcpomatic::Font>("b"),
-		make_shared<dcpomatic::Font>("c")
-	};
-
-	writer.write(fonts);
-
-	BOOST_CHECK_EQUAL(writer._fonts.get(fonts[0]), "a");
-	BOOST_CHECK_EQUAL(writer._fonts.get(fonts[1]), "b");
-	BOOST_CHECK_EQUAL(writer._fonts.get(fonts[2]), "c");
-}
-
-
-BOOST_AUTO_TEST_CASE (writer_disambiguate_font_ids2)
-{
-	auto film = new_test_film2("writer_disambiguate_font_ids2", {});
-	Writer writer(film, {});
-
-	auto fonts = vector<shared_ptr<dcpomatic::Font>> {
-		make_shared<dcpomatic::Font>("a"),
-		make_shared<dcpomatic::Font>("a"),
-		make_shared<dcpomatic::Font>("a")
-	};
-
-	writer.write(fonts);
-
-	BOOST_CHECK_EQUAL(writer._fonts.get(fonts[0]), "a");
-	BOOST_CHECK_EQUAL(writer._fonts.get(fonts[1]), "a_0");
-	BOOST_CHECK_EQUAL(writer._fonts.get(fonts[2]), "a_1");
-}
-
-
-BOOST_AUTO_TEST_CASE (writer_disambiguate_font_ids3)
-{
-	auto film = new_test_film2("writer_disambiguate_font_ids3", {});
-	Writer writer(film, {});
-
-	auto fonts = vector<shared_ptr<dcpomatic::Font>> {
-		make_shared<dcpomatic::Font>("a_2"),
-		make_shared<dcpomatic::Font>("a_1"),
-		make_shared<dcpomatic::Font>("a_1"),
-		make_shared<dcpomatic::Font>("b")
-	};
-
-	writer.write(fonts);
-
-	BOOST_CHECK_EQUAL(writer._fonts.get(fonts[1]), "a_1");
-	BOOST_CHECK_EQUAL(writer._fonts.get(fonts[0]), "a_2");
-	BOOST_CHECK_EQUAL(writer._fonts.get(fonts[2]), "a_3");
-	BOOST_CHECK_EQUAL(writer._fonts.get(fonts[3]), "b");
-}
-
diff --git a/test/wscript b/test/wscript
index f40568e3c..0c9db3889 100644
--- a/test/wscript
+++ b/test/wscript
@@ -99,6 +99,7 @@ def build(bld):
                  film_metadata_test.cc
                  find_missing_test.cc
                  font_comparator_test.cc
+                 font_id_allocator_test.cc
                  frame_interval_checker_test.cc
                  frame_rate_test.cc
                  guess_crop_test.cc