Give a more informative exception on SubRip parse failures.

[libsub.git] / src / subrip_reader.cc

diff --git a/src/subrip_reader.cc b/src/subrip_reader.cc
index 94a48c09bf4d06741c6cbf931f585537babb8ba4..6fab0ffcbdcfed813a7207dbbcda35d513daa115 100644 (file)
--- a/src/subrip_reader.cc
+++ b/src/subrip_reader.cc
@@ -83,6 +83,12 @@ SubripReader::read (function<optional<string> ()> get_line)
                trim_right_if (*line, boost::is_any_of ("\n\r"));
                remove_unicode_bom (line);
 
+               /* Keep some history in case there is an error to report */
+               _context.push_back (*line);
+               if (_context.size() > 5) {
+                       _context.pop_front ();
+               }
+
                switch (state) {
                case COUNTER:
                {
@@ -109,7 +115,13 @@ SubripReader::read (function<optional<string> ()> get_line)
 
                        boost::algorithm::split (p, *line, boost::algorithm::is_any_of (" "));
                        if (p.size() != 3 && p.size() != 7) {
-                               throw SubripError (*line, "a time/position line");
+                               for (int i = 0; i < 2; ++i) {
+                                       optional<string> ex = get_line ();
+                                       if (ex) {
+                                               _context.push_back (*ex);
+                                       }
+                               }
+                               throw SubripError (*line, "a time/position line", _context);
                        }
 
                        rs.from = convert_time (p[0]);
@@ -138,7 +150,7 @@ SubripReader::convert_time (string t)
        vector<string> a;
        boost::algorithm::split (a, t, boost::is_any_of (":"));
        if (a.size() != 3) {
-               throw SubripError (t, "time in the format h:m:s,ms");
+               throw SubripError (t, "time in the format h:m:s,ms", _context);
        }
 
        vector<string> b;