Possible workaround for Qt open file dialog in 4.8.2 failling on some linux distros. Fixes #1022019 (Cannot add any book)

src/calibre/gui2/__init__.py

@@ -581,6 +581,7 @@ class FileDialog(QObject):
         if not isinstance(initial_dir, basestring):
             initial_dir = os.path.expanduser(default_dir)
         self.selected_files = []
+        with SanitizeLibraryPath():
             if mode == QFileDialog.AnyFile:
                 f = unicode(QFileDialog.getSaveFileName(parent, title, initial_dir, ftext, ""))
                 if f:
@@ -857,16 +858,26 @@ class Application(QApplication):
 
 _store_app = None
 
-def open_url(qurl):
-    paths = os.environ.get('LD_LIBRARY_PATH',
-                '').split(os.pathsep)
-    paths = [x for x in paths if x]
+class SanitizeLibraryPath(object):
+    '''Remove the bundled calibre libraries from LD_LIBRARY_PATH on linux. This
+    is needed to prevent library conflicts when launching external utilities.'''
+
+    def __enter__(self):
+        self.orig = os.environ.get('LD_LIBRARY_PATH', '')
+        self.changed = False
+        paths = [x for x in self.orig.split(os.pathsep) if x]
         if isfrozen and islinux and paths:
             npaths = [x for x in paths if x != sys.frozen_path+'/lib']
             os.environ['LD_LIBRARY_PATH'] = os.pathsep.join(npaths)
+            self.changed = True
+
+    def __exit__(self, *args):
+        if self.changed:
+            os.environ['LD_LIBRARY_PATH'] = self.orig
+
+def open_url(qurl):
+    with SanitizeLibraryPath():
         QDesktopServices.openUrl(qurl)
-    if isfrozen and islinux and paths:
-        os.environ['LD_LIBRARY_PATH'] = os.pathsep.join(paths)
 
 def get_current_db():
     '''