Merge ubiquity:only-start-installing-once into ubiquity:master

[Iain Lane]

Don't start installing a second time after going timezone -> user setup -> timezone -> user setup again.

This might partially reopen https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1797579 in that the location selected the second time might suffer from that bug.

Only merge one of this and:

  https://code.launchpad.net/~ubuntu-installer/ubiquity/+git/ubiquity/+merge/357618

Unmerged commits

99b7e3a... by Iain Lane on 2018-10-22

gtk,kde: Don't start installing multiple times

If we go back and forth between timezone and usersetup multiple times,
we can end up restarting debconf under an in-progress installation
process or starting the installation multiple times. This is obviously
bad, and can end up with the installer crashing.

Only restart debconf and start the installation the *first* time the
user clicks next from the timezone step.

https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1799097

diff --git a/ubiquity/frontend/gtk_ui.py b/ubiquity/frontend/gtk_ui.py
index e63046c..ab76c86 100644
--- a/ubiquity/frontend/gtk_ui.py
+++ b/ubiquity/frontend/gtk_ui.py
@@ -587,6 +587,29 @@ class Wizard(BaseFrontend):
 
         gsettings.set(gs_schema, gs_key, gs_value)
 
+    def disable_screen_blanking(self):
+        gs_schema = 'org.gnome.desktop.session'
+        gs_key = 'idle-delay'
+        gs_previous = '%s/%s' % (gs_schema, gs_key)
+        if gs_previous in self.gsettings_previous:
+            return
+
+        gs_value = gsettings.get(gs_schema, gs_key)
+        self.gsettings_previous[gs_previous] = gs_value
+
+        if gs_value:
+            gsettings.set(gs_schema, gs_key, 0)
+
+        atexit.register(self.enable_screen_blanking)
+
+    def enable_screen_blanking(self):
+        gs_schema = 'org.gnome.desktop.session'
+        gs_key = 'idle-delay'
+        gs_previous = '%s/%s' % (gs_schema, gs_key)
+        gs_value = self.gsettings_previous[gs_previous]
+
+        gsettings.set(gs_schema, gs_key, gs_value)
+
     def disable_powermgr(self):
         gs_schema = 'org.gnome.settings-daemon.plugins.power'
         gs_key = 'active'
@@ -738,6 +761,7 @@ class Wizard(BaseFrontend):
 
         self.disable_volume_manager()
         self.disable_screensaver()
+        self.disable_screen_blanking()
         self.disable_powermgr()
 
         if 'UBIQUITY_ONLY' in os.environ:
@@ -1699,12 +1723,14 @@ class Wizard(BaseFrontend):
             dbfilter.start(auto_process=True)
 
         elif finished_step == 'ubi-timezone':
-            self.timezone_set = True
-            # Flush changes to the database so that when the parallel db
-            # starts, it does so with the most recent changes.
-            self.stop_debconf()
-            self.start_debconf()
-            self.maybe_start_installing()
+            # Only do this once; restarting debconf under the installer is bad.
+            if not self.timezone_set:
+                # Flush changes to the database so that when the parallel db
+                # starts, it does so with the most recent changes.
+                self.stop_debconf()
+                self.start_debconf()
+                self.timezone_set = True
+                self.maybe_start_installing()
 
         elif finished_step == 'ubiquity.components.partman_commit':
             self.partitioned = True
diff --git a/ubiquity/frontend/kde_ui.py b/ubiquity/frontend/kde_ui.py
index 9a285a5..1f537b5 100644
--- a/ubiquity/frontend/kde_ui.py
+++ b/ubiquity/frontend/kde_ui.py
@@ -1345,12 +1345,14 @@ class Wizard(BaseFrontend):
             dbfilter.start(auto_process=True)
 
         elif finished_step == 'ubi-timezone':
-            self.timezone_set = True
-            # Flush changes to the database so that when the parallel db
-            # starts, it does so with the most recent changes.
-            self.stop_debconf()
-            self.start_debconf()
-            self.maybe_start_installing()
+            # Only do this once; restarting debconf under the installer is bad.
+            if not self.timezone_set:
+                # Flush changes to the database so that when the parallel db
+                # starts, it does so with the most recent changes.
+                self.stop_debconf()
+                self.start_debconf()
+                self.timezone_set = True
+                self.maybe_start_installing()
 
         elif finished_step == 'ubiquity.components.partman_commit':
             self.partitioned = True
diff --git a/ubiquity/gsettings.py b/ubiquity/gsettings.py
index 7f06f6e..7b1cced 100644
--- a/ubiquity/gsettings.py
+++ b/ubiquity/gsettings.py
@@ -68,6 +68,8 @@ def get(schema, key, user=None):
     # Parse ints
     if value.isdigit():
         return int(value)
+    if value.startswith('uint32'):  # uint32 100
+        return int(value.split()[1])
 
     # Parse booleans
     if value == 'false':