* do not set to SIG_DFL, set it to what handler was used before.

* api.finalize also is critical for system health.

pisi/api.py

@@ -116,7 +116,7 @@ def init(database = True, write = True,
 
 def finalize():
     if ctx.initialized:
-    
+        ctx.disable_keyboard_interrupts()
         if ctx.log:
             ctx.loghandler.flush()
             ctx.log.removeHandler(ctx.loghandler)
@@ -145,6 +145,7 @@ def finalize():
         ctx.ui.debug('PiSi API finalized')
         ctx.ui.close()
         ctx.initialized = False
+        ctx.enable_keyboard_interrupts()
 
 def list_installed():
     '''returns a set of installed package names'''

pisi/signalhandler.py

@@ -16,39 +16,37 @@ exception = {
     signal.SIGINT:KeyboardInterrupt
     }
 
+class Signal:
+    def __init__(self, sig):
+        self.signal = sig
+        self.oldhandler = signal.getsignal(sig)
+        self.pending = False
+
 class SignalHandler:
 
     def __init__(self):
-        self.pending_signals = []
-        self.disabled_signals = []
+        self.signals = {}
 
     def signal_handler(self, sig, frame):
         signal.signal(sig, signal.SIG_IGN)
-        if sig not in self.pending_signals:
-            self.pending_signals.append(sig)
-            
-    def clear_pending_signal(self, sig):
-        if sig in self.pending_signals:
-            self.pending_signals.remove(sig)
+        self.signals[sig].pending = True
             
     def disable_signal(self, sig):
-        signal.signal(sig, self.signal_handler)
-
-        if sig not in self.disabled_signals:
-            self.disabled_signals.append(sig)
+        if sig not in self.signals.keys():
+            self.signals[sig] = Signal(sig)
+            signal.signal(sig, self.signal_handler)
 
     def enable_signal(self, sig):
-        signal.signal(sig, signal.SIG_DFL)
-
-        if sig in self.disabled_signals:
-            self.disabled_signals.remove(sig)
-
-        if sig in self.pending_signals:
-            self.clear_pending_signal(sig)
-            raise exception[sig]
+        if sig in self.signals.keys():
+            oldhandler = self.signals[sig].oldhandler
+            pending = self.signals[sig].pending
+            del self.signals[sig]
+            signal.signal(sig, oldhandler)
+            if pending:
+                raise exception[sig]
 
     def signal_disabled(self, sig):
-        return sig in self.disabled_signals
+        return sig in self.signals.keys()
 
     def signal_pending(self, sig):
-        return sig in self.pending_signals
+        return self.signal_disabled(sig) and self.signals[sig].pending