From 6a594e6b877b3f9387da157e7a343e32ab06f25e Mon Sep 17 00:00:00 2001
From: Moritz Bunkus <moritz@bunkus.org>
Date: Tue, 3 Nov 2015 20:59:45 +0100
Subject: [PATCH] mkvmerge: don't generate segment UIDs for discarded segments
 on splitting

Fixes #1497.
---
 ChangeLog                                     |  4 ++
 src/merge/output_control.cpp                  |  3 ++
 tests/results.txt                             |  1 +
 ...splitting_by_parts_with_segment_linking.rb | 49 +++++++++++++++++++
 4 files changed, 57 insertions(+)
 create mode 100755 tests/test-508splitting_by_parts_with_segment_linking.rb

diff --git a/ChangeLog b/ChangeLog
index d23ad2fac..9b49e8fdd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2015-11-03  Moritz Bunkus  <moritz@bunkus.org>
 
+        * mkvmerge: bug fix: fixed the values of the "previous/next
+        segment UID" elements when splitting by parts with segment linking
+        enabled. Fixes #1497.
+
         * mkvmerge: bug fix: mkvmerge no longer creates a "next segment
         UID" field in the last file when splitting and segment linking is
         active.
diff --git a/src/merge/output_control.cpp b/src/merge/output_control.cpp
index 9b391f462..6279309e7 100644
--- a/src/merge/output_control.cpp
+++ b/src/merge/output_control.cpp
@@ -497,6 +497,9 @@ rerender_ebml_head() {
 
 static void
 generate_segment_uids() {
+  if (g_cluster_helper->discarding())
+    return;
+
   // Generate the segment UIDs.
   if (hack_engaged(ENGAGE_NO_VARIABLE_DATA)) {
     s_seguid_current.zero_content();
diff --git a/tests/results.txt b/tests/results.txt
index 37d378a50..855ff14f6 100644
--- a/tests/results.txt
+++ b/tests/results.txt
@@ -353,3 +353,4 @@ T_504dts_96_24_identification:1837ab5b411944e143f9dae6fe6436d8-bb7c41b5aa1b57f18
 T_505cisco_talos_can_0036:bf0fedc494cf99a0920d7a6e69edf952-6ef415b0f84d3e5dd435244362a37584:passed:20151020-161153:0.071686357
 T_506cisco_talos_can_0037:5461288548eac976164cd13f01bc9426-ed695caee29b1456da8629d38321ec9c-92b7169fc05ddf54c46816869c108f31-54a55a6d87bd4c08269891efb03980b3-fef3d018523c7d1fbed763f6666c1ae2-ac584cc44854f9396739df6e93d78acc-b415b2ef2a6dddf5d89733446fae2970-dd53fee23372c569d35e0b2918d86239:passed:20151020-161234:0.319298931
 T_507rerender_track_headers:7b16f08b7858a1d332516a6fb25a184b-ac9514a1f09f26ac0cb2f527ec2de0b7:passed:20151022-104930:2.573204876
+T_508splitting_by_parts_with_segment_linking:existence0-true-true-true-existence1-true-true-true-existence2-true-true-true-equality_previous-true-true-equality_next-true-true:passed:20151103-204257:0.111807853
diff --git a/tests/test-508splitting_by_parts_with_segment_linking.rb b/tests/test-508splitting_by_parts_with_segment_linking.rb
new file mode 100755
index 000000000..4767e4925
--- /dev/null
+++ b/tests/test-508splitting_by_parts_with_segment_linking.rb
@@ -0,0 +1,49 @@
+#!/usr/bin/ruby -w
+
+# T_508splitting_by_parts_with_segment_linking
+describe "mkvmerge / splitting by parts with segment linking enabled"
+
+self.sys "../src/mkvmerge -o #{tmp} data/avi/v-h264-aac.avi --split parts:00:00:00-00:00:10,00:00:30-00:00:40,00:00:50- --link", :keep_tmp => true, :exit_code => :success
+
+test "segment UIDs" do
+  uids   = []
+  result = []
+
+  (1..3).each do |idx|
+    uids << info("#{tmp}-00#{idx}", :output => :return).
+      first.
+      select { |line| /segment uid/i.match(line) }.
+      map    { |line| line.gsub(/^\| *\+ */, '').chomp.downcase.split(/ *uid: */) }.
+      to_h
+  end
+
+  result << "existence0"
+
+  result <<  uids[0]['previous segment'].nil?
+  result << !uids[0]['segment'].nil?
+  result << !uids[0]['next segment'].nil?
+
+  result << "existence1"
+
+  result << !uids[1]['previous segment'].nil?
+  result << !uids[1]['segment'].nil?
+  result << !uids[1]['next segment'].nil?
+
+  result << "existence2"
+
+  result << !uids[2]['previous segment'].nil?
+  result << !uids[2]['segment'].nil?
+  result <<  uids[2]['next segment'].nil?
+
+  result << "equality_previous"
+
+  result << (uids[0]['segment'] == uids[1]['previous segment'])
+  result << (uids[1]['segment'] == uids[2]['previous segment'])
+
+  result << "equality_next"
+
+  result << (uids[1]['segment'] == uids[0]['next segment'])
+  result << (uids[2]['segment'] == uids[1]['next segment'])
+
+  result.map(&:to_s).join('-')
+end