fix mem leaks in dialogs

- ensure we're cleaning them up after they're rejected
- run the garbage collector afterwards so the qwebengineprocess
  instances get cleaned up

aqt/about.py

@@ -7,8 +7,9 @@ import aqt.forms
 from aqt import appVersion
 from aqt.utils import openLink
 
-def show(parent):
-    dialog = QDialog(parent)
+def show(mw):
+    dialog = QDialog(mw)
+    mw.setupDialogGC(dialog)
     abt = aqt.forms.about.Ui_About()
     abt.setupUi(dialog)
     abouttext = "<center><img src='qrc:/icons/anki-logo-thin.png'></center>"

aqt/addcards.py

@@ -16,6 +16,7 @@ class AddCards(QDialog):
 
     def __init__(self, mw):
         QDialog.__init__(self, None, Qt.Window)
+        mw.setupDialogGC(self)
         self.mw = mw
         self.form = aqt.forms.addcards.Ui_Dialog()
         self.form.setupUi(self)

aqt/browser.py

@@ -466,6 +466,7 @@ class Browser(QMainWindow):
         aqt.dialogs.close("Browser")
         self.teardownHooks()
         self.mw.maybeReset()
+        self.mw.gcWindow(self)
         evt.accept()
 
     def canClose(self):
@@ -1375,6 +1376,7 @@ update cards set usn=?, mod=?, did=? where id in """ + scids,
 
     def onFindDupes(self):
         d = QDialog(self)
+        self.mw.setupDialogGC(d)
         frm = aqt.forms.finddupes.Ui_Dialog()
         frm.setupUi(d)
         restoreGeom(d, "findDupes")

aqt/clayout.py

@@ -20,6 +20,7 @@ class CardLayout(QDialog):
 
     def __init__(self, mw, note, ord=0, parent=None, addMode=False):
         QDialog.__init__(self, parent or mw, Qt.Window)
+        mw.setupDialogGC(self)
         self.mw = aqt.mw
         self.parent = parent or mw
         self.note = note

aqt/main.py

@@ -5,6 +5,8 @@
 import re
 import signal
 import zipfile
+import gc
+import time
 
 from send2trash import send2trash
 from aqt.qt import *
@@ -1139,3 +1141,22 @@ Please ensure a profile is open and Anki is not busy, then try again."""),
             return
         # import
         self.handleImport(buf)
+
+    # GC
+    ##########################################################################
+    # run the garbage collector after object is deleted so we don't leave
+    # expensive web engine processes lying around
+
+    def setupDialogGC(self, obj):
+        obj.finished.connect(lambda o=obj: self.gcWindow(obj))
+
+    def gcWindow(self, obj):
+        obj.deleteLater()
+        t = QTimer(self)
+        t.timeout.connect(self._onCollect)
+        t.setSingleShot(True)
+        # will run next time queue is idle
+        t.start(0)
+
+    def _onCollect(self):
+        gc.collect()

aqt/stats.py

@@ -14,6 +14,7 @@ class DeckStats(QDialog):
 
     def __init__(self, mw):
         QDialog.__init__(self, mw, Qt.Window)
+        mw.setupDialogGC(self)
         self.mw = mw
         self.name = "deckStats"
         self.period = 0