Add a check whether print works.

BUGS

@@ -78,10 +78,6 @@ Upstream Bugs
     Asked on SO: http://stackoverflow.com/q/23499159/2085149
     TODO: report Qt bug
 
-- Printing under windows produced blank pages
-    https://bugreports.qt-project.org/browse/QTBUG-19571
-    If this isn't fixed in Qt 5.3, bug should be reopened.
-
 - QWebElement needs geometries()
     https://bugreports.qt-project.org/browse/QTBUG-38698
 

qutebrowser/browser/commands.py

@@ -35,7 +35,8 @@ import qutebrowser.utils.message as message
 import qutebrowser.utils.webelem as webelem
 import qutebrowser.browser.quickmarks as quickmarks
 import qutebrowser.utils.log as log
-from qutebrowser.utils.misc import check_overflow, shell_escape
+from qutebrowser.utils.misc import (check_overflow, shell_escape,
+                                    check_print_compat)
 from qutebrowser.utils.editor import ExternalEditor
 from qutebrowser.commands.exceptions import CommandError
 from qutebrowser.commands.userscripts import UserscriptRunner
@@ -197,6 +198,9 @@ class CommandDispatcher:
         Args:
             count: The tab index to print, or None.
         """
+        if not check_print_compat():
+            raise CommandError("Printing on Qt < 5.3.0 on Windows is broken, "
+                               "please upgrade!")
         tab = self._tabs.cntwidget(count)
         if tab is not None:
             preview = QPrintPreviewDialog()
@@ -210,9 +214,9 @@ class CommandDispatcher:
         Args:
             count: The tab index to print, or None.
         """
-        # QTBUG: We only get blank pages.
-        # https://bugreports.qt-project.org/browse/QTBUG-19571
-        # If this isn't fixed in Qt 5.3, bug should be reopened.
+        if not check_print_compat():
+            raise CommandError("Printing on Qt < 5.3.0 on Windows is broken, "
+                               "please upgrade!")
         tab = self._tabs.cntwidget(count)
         if tab is not None:
             printdiag = QPrintDialog()

qutebrowser/browser/webpage.py

@@ -30,7 +30,7 @@ import qutebrowser.utils.message as message
 import qutebrowser.utils.url as urlutils
 import qutebrowser.config.config as config
 import qutebrowser.utils.log as log
-from qutebrowser.utils.misc import read_file
+from qutebrowser.utils.misc import read_file, check_print_compat
 from qutebrowser.utils.usertypes import PromptMode
 
 
@@ -145,6 +145,10 @@ class BrowserPage(QWebPage):
 
     def on_print_requested(self, frame):
         """Handle printing when requested via javascript."""
+        if not check_print_compat():
+            message.error("Printing on Qt < 5.3.0 on Windows is broken, "
+                          "please upgrade!")
+            return
         printdiag = QPrintDialog()
         printdiag.open(lambda: frame.print(printdiag.printer()))
 

qutebrowser/utils/misc.py

@@ -397,6 +397,11 @@ def format_size(size, base=1024, suffix=''):
     return '{:.02f}{}{}'.format(size, prefixes[-1], suffix)
 
 
+def check_print_compat():
+    """Check if printing should work in the given Qt version."""
+    return not (os.name == 'nt' and qt_version_check('5.3.0', operator.lt))
+
+
 class EventLoop(QEventLoop):
 
     """A thin wrapper around QEventLoop.