mpd.py: unset iterating flag if an exception is raised

[python-musicpd.git] / mpd.py

diff --git a/mpd.py b/mpd.py
index 32b51a17e4b324ae79dccd33287c4eae6cc11ebb..380f5b1bd5426ea36c2f040820067e0a79386eb1 100644 (file)
--- a/mpd.py
+++ b/mpd.py
@@ -41,6 +41,9 @@ class CommandListError(MPDError):
 class PendingCommandError(MPDError):
     pass
 
+class IteratingError(MPDError):
+    pass
+
 
 class _NotConnected(object):
     def __getattr__(self, attr):
@@ -159,6 +162,9 @@ class MPDClient(object):
         if self._command_list is not None:
             raise CommandListError("Cannot use fetch_%s in a command list" %
                                    command)
+        if self._iterating:
+            raise IteratingError("Cannot use fetch_%s while iterating" %
+                                 command)
         if not self._pending:
             raise PendingCommandError("No pending commands to fetch")
         if self._pending[0] != command:
@@ -170,6 +176,8 @@ class MPDClient(object):
             return retval()
 
     def _execute(self, command, args):
+        if self._iterating:
+            raise IteratingError("Cannot execute %s while iterating" % command)
         if self._pending:
             raise PendingCommandError("Cannot execute %s with "
                                       "pending commands" % command)
@@ -266,10 +274,18 @@ class MPDClient(object):
         self._command_list = None
         self._fetch_nothing()
 
+    def _iterator_wrapper(self, iterator):
+        try:
+            for item in iterator:
+                yield item
+        finally:
+            self._iterating = False
+
     def _wrap_iterator(self, iterator):
         if not self.iterate:
             return list(iterator)
-        return iterator
+        self._iterating = True
+        return self._iterator_wrapper(iterator)
 
     def _fetch_nothing(self):
         line = self._read_line()
@@ -326,6 +342,7 @@ class MPDClient(object):
 
     def _reset(self):
         self.mpd_version = None
+        self._iterating = False
         self._pending = []
         self._command_list = None
         self._sock = None
@@ -392,6 +409,8 @@ class MPDClient(object):
     def command_list_ok_begin(self):
         if self._command_list is not None:
             raise CommandListError("Already in command list")
+        if self._iterating:
+            raise IteratingError("Cannot begin command list while iterating")
         if self._pending:
             raise PendingCommandError("Cannot begin command list "
                                       "with pending commands")
@@ -401,6 +420,8 @@ class MPDClient(object):
     def command_list_end(self):
         if self._command_list is None:
             raise CommandListError("Not in command list")
+        if self._iterating:
+            raise IteratingError("Already iterating over a command list")
         self._write_command("command_list_end")
         return self._fetch_command_list()