Fix #4007 (Download Now doesn't work after Stop Selected Job)

Changelog.yaml

@@ -43,6 +43,9 @@
       tickets: [3328]
 
     - title: "Linux device detection: Switch to using libusb1 to enumerate devices on system."
+      description: >
+        "If you are building for source, the libusb1 headers and library are now required at
+        compile time."
 
   bug fixes:
 
@@ -65,7 +68,7 @@
     - title: "Save to disk: Fix {pubdate} format string in template being ignored"
       tickets: [4140]
 
-    - title: Replace rotating hourglass with a more efficient bust indicator
+    - title: "Replace rotating hourglass with a more efficient busy indicator."
 
     - title: "PML Input: Make footnotes and sidebars display better"
 
@@ -78,6 +81,9 @@
     - title: "Fix PocketBook 360 driver on windows when no SD card is inserted"
       tickets: [4182]
 
+    - title: "Fix stopping of a recipe download would prevent it from being re-downloaded until a calibre restart"
+      tickets: [4007, 4158]
+
   new recipes:
 
     - title: Rzeczpospolita OnLine

src/calibre/devices/libusb1.py

@@ -9,7 +9,7 @@ __docformat__ = 'restructuredtext en'
 
 from calibre.constants import plugins
 
-libusb, libusb_err = plugins['libusb']
+libusb, libusb_err = plugins.get('libusb', (None, 'Wrong platform'))
 
 def scan():
     if libusb_err:

src/calibre/gui2/dialogs/scheduler.py

@@ -287,6 +287,14 @@ class Scheduler(QObject):
         finally:
             self.lock.unlock()
 
+    def recipe_download_failed(self, arg):
+        self.lock.lock()
+        try:
+            self.download_queue.remove(arg['urn'])
+        finally:
+            self.lock.unlock()
+
+
     def download_clicked(self, urn):
         if urn is not None:
             return self.download(urn)

src/calibre/gui2/ui.py

@@ -1224,6 +1224,7 @@ class Main(MainWindow, Ui_MainWindow, DeviceGUI):
         temp_files, fmt, arg = self.conversion_jobs.pop(job)
         pt = temp_files[0]
         if job.failed:
+            self.scheduler.recipe_download_failed(arg)
             return self.job_exception(job)
         id = self.library_view.model().add_news(pt.name, arg)
         self.library_view.model().reset()