Convert handler to use property-reset instead of property-del

There was also one case of triggering property-{del => reset}
synthetically on default value change. Adjust it too and drop -pre-
event call in that case.

QubesOS/qubes-issues#5834

qubes/app.py

@@ -1530,9 +1530,7 @@ class Qubes(qubes.PropertyHolder):
         for vm in self.domains:
             if hasattr(vm, 'provides_network') and not vm.provides_network and \
                     hasattr(vm, 'netvm') and vm.property_is_default('netvm'):
-                # fire property-del:netvm as it is responsible for resetting
+                # fire property-reset:netvm as it is responsible for resetting
                 # netvm to it's default value
-                vm.fire_event('property-pre-del:netvm', pre_event=True,
+                vm.fire_event('property-reset:netvm',
-                              name='netvm', oldvalue=oldvalue)
-                vm.fire_event('property-del:netvm',
                               name='netvm', oldvalue=oldvalue)

qubes/ext/audio.py

@@ -48,9 +48,8 @@ class AUDIO(qubes.ext.Extension):
                 self.on_property_set(vm, event, name='audiovm',
                                      newvalue=vm.audiovm)
 
-    # property-del <=> property-reset-to-default
+    @qubes.ext.handler('property-reset:audiovm')
-    @qubes.ext.handler('property-del:audiovm')
+    def on_property_reset(self, subject, event, name, oldvalue=None):
-    def on_property_del(self, subject, event, name, oldvalue=None):
         newvalue = getattr(subject, 'audiovm', None)
         self.on_property_set(subject, event, name, newvalue, oldvalue)
 

qubes/ext/core_features.py

@@ -75,8 +75,8 @@ class CoreFeatures(qubes.ext.Extension):
         # pylint: disable=unused-argument
         self.set_servicevm_feature(subject)
 
-    @qubes.ext.handler('property-del:provides_network')
+    @qubes.ext.handler('property-reset:provides_network')
-    def on_property_del(self, subject, event, name):
+    def on_property_reset(self, subject, event, name):
         # pylint: disable=unused-argument
         self.set_servicevm_feature(subject)
 

qubes/ext/gui.py

@@ -58,9 +58,8 @@ class GUI(qubes.ext.Extension):
             if 'guivm-' + vm.guivm.name not in vm.tags:
                 self.on_property_set(vm, event, name='guivm', newvalue=vm.guivm)
 
-    # property-del <=> property-reset-to-default
+    @qubes.ext.handler('property-reset:guivm')
-    @qubes.ext.handler('property-del:guivm')
+    def on_property_reset(self, subject, event, name, oldvalue=None):
-    def on_property_del(self, subject, event, name, oldvalue=None):
         newvalue = getattr(subject, 'guivm', None)
         self.on_property_set(subject, event, name, newvalue, oldvalue)
 

qubes/firewall.py

@@ -329,8 +329,8 @@ class Rule(qubes.PropertyHolder):
         if newvalue not in ('icmp',):
             self.icmptype = qubes.property.DEFAULT
 
-    @qubes.events.handler('property-del:proto')
+    @qubes.events.handler('property-reset:proto')
-    def on_del_proto(self, event, name, oldvalue):
+    def on_reset_proto(self, event, name, oldvalue):
         # pylint: disable=unused-argument
         self.dstports = qubes.property.DEFAULT
         self.icmptype = qubes.property.DEFAULT

qubes/vm/appvm.py

@@ -112,8 +112,8 @@ class AppVM(qubes.vm.qubesvm.QubesVM):
         '''  # pylint: disable=unused-argument
         assert self.template
 
-    @qubes.events.handler('property-pre-del:template')
+    @qubes.events.handler('property-pre-reset:template')
-    def on_property_pre_del_template(self, event, name, oldvalue=None):
+    def on_property_pre_reset_template(self, event, name, oldvalue=None):
         '''Forbid deleting template of running VM
         '''  # pylint: disable=unused-argument,no-self-use
         raise qubes.exc.QubesValueError('Cannot unset template')

qubes/vm/dispvm.py

@@ -134,7 +134,7 @@ class DispVM(qubes.vm.qubesvm.QubesVM):
         assert self.template
 
     @qubes.events.handler('property-pre-set:template',
-        'property-pre-del:template')
+        'property-pre-reset:template')
     def on_property_pre_set_template(self, event, name, newvalue=None,
             oldvalue=None):
         ''' Disposable VM cannot have template changed '''

qubes/vm/mix/net.py

@@ -406,8 +406,8 @@ class NetVMMixin(qubes.events.Emitter):
             '/connected-ips6',
             ' '.join(connected_ips6))
 
-    @qubes.events.handler('property-pre-del:netvm')
+    @qubes.events.handler('property-pre-reset:netvm')
-    def on_property_pre_del_netvm(self, event, name, oldvalue=None):
+    def on_property_pre_reset_netvm(self, event, name, oldvalue=None):
         ''' Sets the the NetVM to default NetVM '''
         # pylint: disable=unused-argument
         # we are changing to default netvm
@@ -419,8 +419,8 @@ class NetVMMixin(qubes.events.Emitter):
         self.fire_event('property-pre-set:netvm', pre_event=True,
             name='netvm', newvalue=newvalue, oldvalue=oldvalue)
 
-    @qubes.events.handler('property-del:netvm')
+    @qubes.events.handler('property-reset:netvm')
-    def on_property_del_netvm(self, event, name, oldvalue=None):
+    def on_property_reset_netvm(self, event, name, oldvalue=None):
         ''' Sets the the NetVM to default NetVM '''
         # pylint: disable=unused-argument
         # we are changing to default netvm

qubes/vm/qubesvm.py

@@ -1006,8 +1006,8 @@ class QubesVM(qubes.vm.mix.net.NetVMMixin, qubes.vm.BaseVM):
             raise qubes.exc.QubesException(
                 'Failed to set autostart for VM in systemd')
 
-    @qubes.events.handler('property-pre-del:autostart')
+    @qubes.events.handler('property-pre-reset:autostart')
-    def on_property_pre_del_autostart(self, event, name, oldvalue=None):
+    def on_property_pre_reset_autostart(self, event, name, oldvalue=None):
         # pylint: disable=unused-argument
         if oldvalue:
             retcode = subprocess.call(