Avoid a possible deadlock in the fix for 2.3.1

pqiv used MagickWandTerminus as atexit(), but MagickWand is not
reentrant. Lock the mutex in the atexit() handler to prevent active
MagickWand methods in the loader thread from deadlocking.

README.markdown

@@ -118,6 +118,9 @@ Known bugs
 Changelog
 ---------
 
+pqiv 2.3.2
+ * Avoid a possible deadlock in the fix for 2.3.1
+
 pqiv 2.3.1
  * Properly handle if a user closes pqiv while the image loader is still active
 

backends/wand.c

@@ -276,6 +276,12 @@ void file_type_wand_draw(file_t *file, cairo_t *cr) {/*{{{*/
 	}
 }/*}}}*/
 
+static void file_type_wand_exit_handler() {/*{{{*/
+	G_LOCK(magick_wand_global_lock);
+	MagickWandTerminus();
+	G_UNLOCK(magick_wand_global_lock);
+}/*}}}*/
+
 void file_type_wand_initializer(file_type_handler_t *info) {/*{{{*/
 	// Fill the file filter pattern
 	MagickWandGenesis();
@@ -298,7 +304,7 @@ void file_type_wand_initializer(file_type_handler_t *info) {/*{{{*/
 
 	// We need to register MagickWandTerminus(), imageMagick's exit handler, to
 	// cleanup temporary files when pqiv exits.
-	atexit(MagickWandTerminus);
+	atexit(file_type_wand_exit_handler);
 
 	// Magick Wand does not give us MIME types. Manually add the most interesting one:
 	gtk_file_filter_add_mime_type(info->file_types_handled, "image/vnd.adobe.photoshop");

pqiv.c

@@ -3765,9 +3765,11 @@ gpointer load_images_thread(gpointer user_data) {/*{{{*/
 
 	load_images(&global_argc, global_argv);
 
-	if(bostree_node_count(file_tree) == 0) {
-		g_printerr("No images left to display.\n");
-		exit(1);
+	if(file_tree_valid) {
+		if(bostree_node_count(file_tree) == 0) {
+			g_printerr("No images left to display.\n");
+			exit(1);
+		}
 	}
 
 	if(user_data != NULL) {

pqiv.h

@@ -29,7 +29,7 @@
 #include "lib/bostree.h"
 
 #ifndef PQIV_VERSION
-#define PQIV_VERSION "2.3.1"
+#define PQIV_VERSION "2.3.2"
 #endif
 
 #define FILE_FLAGS_ANIMATION      (guint)(1)