Fix crash on cancellation of encodes during check of image data; allow cancellation during this time (#679).

3 files changed, 15 insertions, 7 deletions

diff --git a/src/lib/job.cc b/src/lib/job.cc
index d9715aa18..87e4fb3d3 100644
--- a/src/lib/job.cc
+++ b/src/lib/job.cc
@@ -247,6 +247,12 @@ Job::set_progress (float p, bool force)
 		return;
 	}
 
+	set_progress_common (p);
+}
+
+void
+Job::set_progress_common (optional<float> p)
+{
 	boost::mutex::scoped_lock lm (_progress_mutex);
 	_progress = p;
 	boost::this_thread::interruption_point ();
@@ -315,11 +321,7 @@ Job::set_error (string s, string d)
 void
 Job::set_progress_unknown ()
 {
-	boost::mutex::scoped_lock lm (_progress_mutex);
-	_progress.reset ();
-	lm.unlock ();
-
-	emit (boost::bind (boost::ref (Progress)));
+	set_progress_common (optional<float> ());
 }
 
 /** @return Human-readable status of this job */
diff --git a/src/lib/job.h b/src/lib/job.h
index 06a341f40..4e52e76a1 100644
--- a/src/lib/job.h
+++ b/src/lib/job.h
@@ -106,6 +106,7 @@ protected:
 private:
 
 	void run_wrapper ();
+	void set_progress_common (boost::optional<float> p);
 
 	boost::thread* _thread;
 
diff --git a/src/lib/writer.cc b/src/lib/writer.cc
index 58b2b8a91..9c4a194e8 100644
--- a/src/lib/writer.cc
+++ b/src/lib/writer.cc
@@ -147,9 +147,14 @@ Writer::Writer (shared_ptr<const Film> film, weak_ptr<Job> j)
 		throw InvalidSignerError ();
 	}
 
-	_thread = new boost::thread (boost::bind (&Writer::thread, this));
-
 	job->sub (_("Encoding image data"));
+
+	/* Do this last; if something after this line were to throw an exception
+	   (say if Job::sub was interrupted by cancel) this thread would never
+	   get properly cleaned up but the Writer object would go away underneath
+	   it.
+	*/
+	_thread = new boost::thread (boost::bind (&Writer::thread, this));
 }
 
 Writer::~Writer ()