Add verify check for empty <Text> nodes in timed text.

6 files changed, 92 insertions, 4 deletions

diff --git a/src/verify.cc b/src/verify.cc
index c8307aa5..e7a55d4c 100644
--- a/src/verify.cc
+++ b/src/verify.cc
@@ -778,6 +778,7 @@ verify_closed_caption_asset (
 }
 
 
+/** Check the timing of the individual subtitles and make sure there are no empty <Text> nodes */
 static
 void
 verify_text_details (
@@ -795,11 +796,12 @@ verify_text_details (
 	auto too_close = false;
 	auto too_early = false;
 	auto reel_overlap = false;
+	auto empty_text = false;
 	/* current reel start time (in editable units) */
 	int64_t reel_offset = 0;
 
 	std::function<void (cxml::ConstNodePtr, optional<int>, optional<Time>, int, bool)> parse;
-	parse = [&parse, &last_out, &too_short, &too_close, &too_early, &reel_offset](cxml::ConstNodePtr node, optional<int> tcr, optional<Time> start_time, int er, bool first_reel) {
+	parse = [&parse, &last_out, &too_short, &too_close, &too_early, &empty_text, &reel_offset](cxml::ConstNodePtr node, optional<int> tcr, optional<Time> start_time, int er, bool first_reel) {
 		if (node->name() == "Subtitle") {
 			Time in (node->string_attribute("TimeIn"), tcr);
 			if (start_time) {
@@ -824,11 +826,26 @@ verify_text_details (
 				}
 			}
 			last_out = reel_offset + out.as_editable_units_floor(er);
-		} else {
-			for (auto i: node->node_children()) {
-				parse(i, tcr, start_time, er, first_reel);
+		} else if (node->name() == "Text") {
+			std::function<bool (cxml::ConstNodePtr)> node_has_content = [&](cxml::ConstNodePtr node) {
+				if (!node->content().empty()) {
+					return true;
+				}
+				for (auto i: node->node_children()) {
+					if (node_has_content(i)) {
+						return true;
+					}
+				}
+				return false;
+			};
+			if (!node_has_content(node)) {
+				empty_text = true;
 			}
 		}
+
+		for (auto i: node->node_children()) {
+			parse(i, tcr, start_time, er, first_reel);
+		}
 	};
 
 	for (auto i = 0U; i < reels.size(); ++i) {
@@ -896,6 +913,12 @@ verify_text_details (
 			VerificationNote::Type::ERROR, VerificationNote::Code::SUBTITLE_OVERLAPS_REEL_BOUNDARY
 		});
 	}
+
+	if (empty_text) {
+		notes.push_back ({
+			VerificationNote::Type::WARNING, VerificationNote::Code::EMPTY_TEXT
+		});
+	}
 }
 
 
@@ -1626,6 +1649,8 @@ dcp::note_to_string (VerificationNote note)
 	}
 	case VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED:
 		return "Some aspect of this DCP could not be checked because it is encrypted.";
+	case VerificationNote::Code::EMPTY_TEXT:
+		return "There is an empty <Text> node in a subtitle or closed caption.";
 	}
 
 	return "";
diff --git a/src/verify.h b/src/verify.h
index c0491422..045c12c2 100644
--- a/src/verify.h
+++ b/src/verify.h
@@ -381,6 +381,8 @@ public:
 		MISMATCHED_TIMED_TEXT_DURATION,
 		/** Something could not be verified because content is encrypted and no key is available */
 		MISSED_CHECK_OF_ENCRYPTED,
+		/** Some timed-text XML has an empty <Text> node */
+		EMPTY_TEXT
 	};
 
 	VerificationNote (Type type, Code code)
diff --git a/test/data/empty_but_with_children.xml b/test/data/empty_but_with_children.xml
new file mode 100644
index 00000000..74f3ddb5
--- /dev/null
+++ b/test/data/empty_but_with_children.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<DCSubtitle Version="1.0"><SubtitleID>04a77cb2-3d44-4fea-8817-ce9feb5ad79b</SubtitleID><MovieTitle>DCP</MovieTitle><ReelNumber>1</ReelNumber><Language>Unknown</Language><LoadFont Id="font0" URI="font_0.ttf"/><Font AspectAdjust="1.0" Color="FFFFFFFF" Effect="none" EffectColor="FF000000" Id="font0" Script="normal" Size="42" Underlined="no" Weight="normal"><Subtitle SpotNumber="1" TimeIn="00:00:00:208" TimeOut="00:00:06:031" FadeUpTime="0" FadeDownTime="0"><Text VAlign="bottom" VPosition="10"><Font Italic="no">This</Font><Font Italic="yes"> is </Font><Font Italic="no">wrong.</Font></Text></Subtitle></Font></DCSubtitle>
diff --git a/test/data/empty_text.mxf b/test/data/empty_text.mxf
new file mode 100644
index 00000000..b60c04a4
--- /dev/null
+++ b/test/data/empty_text.mxf
diff --git a/test/data/empty_with_empty_children.xml b/test/data/empty_with_empty_children.xml
new file mode 100644
index 00000000..1e58f20b
--- /dev/null
+++ b/test/data/empty_with_empty_children.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<DCSubtitle Version="1.0"><SubtitleID>04a77cb2-3d44-4fea-8817-ce9feb5ad79b</SubtitleID><MovieTitle>DCP</MovieTitle><ReelNumber>1</ReelNumber><Language>Unknown</Language><LoadFont Id="font0" URI="font_0.ttf"/><Font AspectAdjust="1.0" Color="FFFFFFFF" Effect="none" EffectColor="FF000000" Id="font0" Script="normal" Size="42" Underlined="no" Weight="normal"><Subtitle SpotNumber="1" TimeIn="00:00:00:208" TimeOut="00:00:06:031" FadeUpTime="0" FadeDownTime="0"><Text VAlign="bottom" VPosition="10"><Font Italic="no"></Font><Font Italic="yes"></Font><Font Italic="no"></Font></Text></Subtitle></Font></DCSubtitle>
diff --git a/test/verify_test.cc b/test/verify_test.cc
index 59777fe5..ec4dea9d 100644
--- a/test/verify_test.cc
+++ b/test/verify_test.cc
@@ -760,6 +760,63 @@ BOOST_AUTO_TEST_CASE (verify_invalid_smpte_subtitles)
 }
 
 
+BOOST_AUTO_TEST_CASE (verify_empty_text_node_in_subtitles)
+{
+	path const dir("build/test/verify_empty_text_node_in_subtitles");
+	prepare_directory (dir);
+	copy_file ("test/data/empty_text.mxf", dir / "subs.mxf");
+	auto asset = make_shared<dcp::SMPTESubtitleAsset>(dir / "subs.mxf");
+	auto reel_asset = make_shared<dcp::ReelSMPTESubtitleAsset>(asset, dcp::Fraction(24, 1), 192, 0);
+	auto cpl = write_dcp_with_single_asset (dir, reel_asset);
+
+	check_verify_result (
+		{ dir },
+		{
+			{ dcp::VerificationNote::Type::WARNING, dcp::VerificationNote::Code::EMPTY_TEXT },
+			{ dcp::VerificationNote::Type::WARNING, dcp::VerificationNote::Code::INVALID_SUBTITLE_FIRST_TEXT_TIME },
+			{ dcp::VerificationNote::Type::BV21_ERROR, dcp::VerificationNote::Code::MISSING_SUBTITLE_LANGUAGE, canonical(dir / "subs.mxf") },
+			{ dcp::VerificationNote::Type::BV21_ERROR, dcp::VerificationNote::Code::MISSING_CPL_METADATA, cpl->id(), cpl->file().get() },
+		});
+}
+
+
+/** A <Text> node with no content except some <Font> nodes, which themselves do have content */
+BOOST_AUTO_TEST_CASE (verify_empty_text_node_in_subtitles_with_child_nodes)
+{
+	path const dir("build/test/verify_empty_text_node_in_subtitles_with_child_nodes");
+	prepare_directory (dir);
+	copy_file ("test/data/empty_but_with_children.xml", dir / "subs.xml");
+	auto asset = make_shared<dcp::InteropSubtitleAsset>(dir / "subs.xml");
+	auto reel_asset = make_shared<dcp::ReelInteropSubtitleAsset>(asset, dcp::Fraction(24, 1), 192, 0);
+	auto cpl = write_dcp_with_single_asset (dir, reel_asset, dcp::Standard::INTEROP);
+
+	check_verify_result (
+		{ dir },
+		{
+			{ dcp::VerificationNote::Type::BV21_ERROR, dcp::VerificationNote::Code::INVALID_STANDARD },
+		});
+}
+
+
+/** A <Text> node with no content except some <Font> nodes, which themselves also have no content */
+BOOST_AUTO_TEST_CASE (verify_empty_text_node_in_subtitles_with_empty_child_nodes)
+{
+	path const dir("build/test/verify_empty_text_node_in_subtitles_with_empty_child_nodes");
+	prepare_directory (dir);
+	copy_file ("test/data/empty_with_empty_children.xml", dir / "subs.xml");
+	auto asset = make_shared<dcp::InteropSubtitleAsset>(dir / "subs.xml");
+	auto reel_asset = make_shared<dcp::ReelInteropSubtitleAsset>(asset, dcp::Fraction(24, 1), 192, 0);
+	auto cpl = write_dcp_with_single_asset (dir, reel_asset, dcp::Standard::INTEROP);
+
+	check_verify_result (
+		{ dir },
+		{
+			{ dcp::VerificationNote::Type::BV21_ERROR, dcp::VerificationNote::Code::INVALID_STANDARD },
+			{ dcp::VerificationNote::Type::WARNING, dcp::VerificationNote::Code::EMPTY_TEXT },
+		});
+}
+
+
 BOOST_AUTO_TEST_CASE (verify_external_asset)
 {
 	path const ov_dir("build/test/verify_external_asset");