Handle wrong image/jpg mimetype in unsupportedContent slot.

qutebrowser/browser/webpage.py

@@ -19,6 +19,8 @@
 
 """The main browser widgets."""
 
+from functools import partial
+
 import sip
 from PyQt5.QtCore import pyqtSignal, pyqtSlot, PYQT_VERSION, Qt
 from PyQt5.QtNetwork import QNetworkReply
@@ -29,6 +31,7 @@ from PyQt5.QtWebKitWidgets import QWebPage
 import qutebrowser.utils.message as message
 import qutebrowser.config.config as config
 import qutebrowser.utils.log as log
+import qutebrowser.utils.http as http
 from qutebrowser.network.networkmanager import NetworkManager
 from qutebrowser.utils.misc import read_file
 from qutebrowser.utils.qt import check_print_compat
@@ -63,6 +66,7 @@ class BrowserPage(QWebPage):
         self.setForwardUnsupportedContent(True)
         self.printRequested.connect(self.on_print_requested)
         self.downloadRequested.connect(self.on_download_requested)
+        self.unsupportedContent.connect(self.on_unsupported_content)
         self._view = view
 
         if PYQT_VERSION > 0x050300:
@@ -147,6 +151,11 @@ class BrowserPage(QWebPage):
                                                           suggested_file)
         return True
 
+    def display_content(self, reply, mimetype):
+        """Display a QNetworkReply with an explicitely set mimetype."""
+        self.mainFrame().setContent(reply.readAll(), mimetype, reply.url())
+        reply.deleteLater()
+
     def on_print_requested(self, frame):
         """Handle printing when requested via javascript."""
         if not check_print_compat():
@@ -168,6 +177,36 @@ class BrowserPage(QWebPage):
         reply = self.networkAccessManager().get(request)
         self.start_download.emit(reply)
 
+    @pyqtSlot('QNetworkReply')
+    def on_unsupported_content(self, reply):
+        """Handle an unsupportedContent signal.
+
+        Most likely this will mean we need to download the reply, but we
+        correct for some common errors the server do.
+
+        At some point we might want to implement the MIME Sniffing standard
+        here: http://mimesniff.spec.whatwg.org/
+        """
+        inline, _suggested_filename = http.parse_content_disposition(reply)
+        if not inline:
+            # Content-Disposition: attachment -> force download
+            self.start_download.emit(reply)
+            return
+        mimetype, _rest = http.parse_content_type(reply)
+        if mimetype == 'image/jpg':
+            # Some servers (e.g. the LinkedIn CDN) send a non-standard
+            # image/jpg (instead of image/jpeg, defined in RFC 1341 section
+            # 7.5). If this is the case, we force displaying with a corrected
+            # mimetype.
+            if reply.isFinished():
+                self.display_content(reply, 'image/jpeg')
+            else:
+                reply.finished.connect(
+                    partial(self.display_content, reply, 'image/jpeg'))
+        else:
+            # Unknown mimetype, so download anyways.
+            self.start_download.emit(reply)
+
     def userAgentForUrl(self, url):
         """Override QWebPage::userAgentForUrl to customize the user agent."""
         ua = config.get('network', 'user-agent')

qutebrowser/network/networkmanager.py

@@ -19,8 +19,6 @@
 
 """Our own QNetworkAccessManager."""
 
-from functools import partial
-
 from PyQt5.QtCore import pyqtSlot, PYQT_VERSION, QCoreApplication
 from PyQt5.QtNetwork import QNetworkAccessManager, QNetworkReply
 
@@ -37,7 +35,6 @@ import qutebrowser.utils.log as log
 from qutebrowser.network.qutescheme import QuteSchemeHandler
 from qutebrowser.network.schemehandler import ErrorNetworkReply
 from qutebrowser.utils.usertypes import PromptMode
-from qutebrowser.utils.http import change_content_type
 
 
 class NetworkManager(QNetworkAccessManager):
@@ -162,10 +159,4 @@ class NetworkManager(QNetworkAccessManager):
             reply = super().createRequest(op, req, outgoing_data)
         self._requests.append(reply)
         reply.destroyed.connect(lambda obj: self._requests.remove(obj))
-        # Some servers (e.g. the LinkedIn CDN) send a non-standard image/jpg
-        # header for jpg images. We change this to image/jpeg (defined in RFC
-        # 1341 section 7.5: https://tools.ietf.org/html/rfc1341) so QtWebKit
-        # displays this instead of downloading it.
-        reply.metaDataChanged.connect(
-            partial(change_content_type, reply, {'image/jpg': 'image/jpeg'}))
         return reply

qutebrowser/widgets/tabbedbrowser.py

@@ -166,7 +166,6 @@ class TabbedBrowser(TabWidget):
         tab.hintmanager.openurl.connect(self.openurl)
         self.cur_load_started.connect(self.on_cur_load_started)
         # downloads
-        page.unsupportedContent.connect(self.start_download)
         page.start_download.connect(self.start_download)
         # misc
         tab.titleChanged.connect(partial(self.on_title_changed, tab))