OS X: Use standard locations for GPODDER_HOME. Fixes bug 1912

If ~/gPodder/ does not exist, use ~/Library/Application Support/gPodder/

src/gpodder/__init__.py

@@ -166,8 +166,23 @@ def set_home(new_home):
     if ENV_DOWNLOADS not in os.environ:
         downloads = os.path.join(home, 'Downloads')
 
+def fixup_home(old_home):
+    if ui.osx:
+        new_home = os.path.expanduser(os.path.join('~', 'Library',
+            'Application Support', 'gPodder'))
+
+        # Users who do not have the old home directory, or who have it but also
+        # have the new home directory (to cater to situations where the user
+        # might for some reason or the other have a ~/gPodder/ directory) get
+        # to use the new, more OS X-ish home.
+        if not os.path.exists(old_home) or os.path.exists(new_home):
+            return new_home
+
+    return old_home
+
 # Default locations for configuration and data files
 default_home = os.path.expanduser(os.path.join('~', 'gPodder'))
+default_home = fixup_home(default_home)
 set_home(os.environ.get(ENV_HOME, default_home))
 
 if home != default_home: