1 files changed, 23 insertions, 22 deletions

diff --git a/src/verify.cc b/src/verify.cc
index 1f0d7790..1e27514a 100644
--- a/src/verify.cc
+++ b/src/verify.cc
@@ -81,6 +81,7 @@
 #include <boost/algorithm/string.hpp>
 #include <iostream>
 #include <map>
+#include <numeric>
 #include <regex>
 #include <set>
 #include <vector>
@@ -1200,18 +1201,9 @@ verify_closed_caption_details(Context& context, vector<shared_ptr<Reel>> reels)
 }
 
 
-struct LinesCharactersResult
-{
-	bool warning_length_exceeded = false;
-	bool error_length_exceeded = false;
-	bool line_count_exceeded = false;
-};
-
-
-static
 void
-verify_text_lines_and_characters (
-	shared_ptr<SubtitleAsset> asset,
+dcp::verify_text_lines_and_characters(
+	shared_ptr<const SubtitleAsset> asset,
 	int warning_length,
 	int error_length,
 	LinesCharactersResult* result
@@ -1232,8 +1224,8 @@ verify_text_lines_and_characters (
 		{}
 
 		Time time;
-		int position; //< position from 0 at top of screen to 100 at bottom
-		int characters;
+		int position = 0;   ///< vertical position from 0 at top of screen to 100 at bottom
+		int characters = 0; ///< number of characters in the text of this event
 		shared_ptr<Event> start;
 	};
 
@@ -1252,6 +1244,7 @@ verify_text_lines_and_characters (
 		return 0L;
 	};
 
+	/* Make a list of "subtitle starts" and "subtitle ends" events */
 	for (auto j: asset->subtitles()) {
 		auto text = dynamic_pointer_cast<const SubtitleString>(j);
 		if (text) {
@@ -1261,20 +1254,25 @@ verify_text_lines_and_characters (
 		}
 	}
 
-	std::sort(events.begin(), events.end(), [](shared_ptr<Event> const& a, shared_ptr<Event>const& b) {
+	std::sort(events.begin(), events.end(), [](shared_ptr<Event> const& a, shared_ptr<Event> const& b) {
 		return a->time < b->time;
 	});
 
-	map<int, int> current;
+	/* The number of characters currently displayed at different vertical positions, i.e. on
+	 * what we consider different lines.  Key is the vertical position (0 to 100) and the value
+	 * is a list of the active subtitles in that position.
+	 */
+	map<int, vector<shared_ptr<Event>>> current;
 	for (auto i: events) {
 		if (current.size() > 3) {
 			result->line_count_exceeded = true;
 		}
 		for (auto j: current) {
-			if (j.second > warning_length) {
+			int length = std::accumulate(j.second.begin(), j.second.end(), 0, [](int total, shared_ptr<const Event> event) { return total + event->characters; });
+			if (length > warning_length) {
 				result->warning_length_exceeded = true;
 			}
-			if (j.second > error_length) {
+			if (length > error_length) {
 				result->error_length_exceeded = true;
 			}
 		}
@@ -1282,17 +1280,20 @@ verify_text_lines_and_characters (
 		if (i->start) {
 			/* end of a subtitle */
 			DCP_ASSERT (current.find(i->start->position) != current.end());
-			if (current[i->start->position] == i->start->characters) {
+			auto current_position = current[i->start->position];
+			auto iter = std::find(current_position.begin(), current_position.end(), i->start);
+			if (iter != current_position.end()) {
+				current_position.erase(iter);
+			}
+			if (current_position.empty()) {
 				current.erase(i->start->position);
-			} else {
-				current[i->start->position] -= i->start->characters;
 			}
 		} else {
 			/* start of a subtitle */
 			if (current.find(i->position) == current.end()) {
-				current[i->position] = i->characters;
+				current[i->position] = vector<shared_ptr<Event>>{i};
 			} else {
-				current[i->position] += i->characters;
+				current[i->position].push_back(i);
 			}
 		}
 	}