Fix pasting of empty URLs.

qutebrowser/browser/commands.py

@@ -826,11 +826,11 @@ class CommandDispatcher:
             mode = QClipboard.Clipboard
             target = "Clipboard"
         text = clipboard.text(mode)
-        if not text:
+        if not text.strip():
             raise cmdexc.CommandError("{} is empty.".format(target))
         log.misc.debug("{} contained: '{}'".format(target,
                                                    text.replace('\n', '\\n')))
-        text_urls = enumerate(u for u in text.split('\n') if u)
+        text_urls = enumerate(u for u in text.split('\n') if u.strip())
         for i, text_url in text_urls:
             if not window and i > 0:
                 tab = False

tests/integration/features/conftest.py

@@ -210,6 +210,7 @@ def selection_supported(qapp):
 def fill_clipboard(qtbot, qapp, httpbin, what, content):
     mode = _clipboard_mode(qapp, what)
     content = content.replace('(port)', str(httpbin.port))
+    content = content.replace(r'\n', '\n')
 
     clipboard = qapp.clipboard()
     with qtbot.waitSignal(clipboard.changed):

tests/integration/features/yankpaste.feature

@@ -61,6 +61,11 @@ Feature: Yanking and pasting.
         And I run :paste --sel
         Then the error "Primary selection is empty." should be shown
 
+    Scenario: Pasting with a space in clipboard
+        When I put " " into the clipboard
+        And I run :paste
+        Then the error "Clipboard is empty." should be shown
+
     Scenario: Pasting in a new tab
         Given I open about:blank
         When I run :tab-only
@@ -171,6 +176,18 @@ Feature: Yanking and pasting.
                 - active: true
                   url: http://localhost:*/data/hello3.txt
 
+    Scenario: Pasting multiple urls with an empty one
+        When I open about:blank
+        And I put "http://localhost:(port)/data/hello.txt\n\nhttp://localhost:(port)/data/hello2.txt" into the clipboard
+        And I run :paste -t
+        Then no crash should happen
+
+    Scenario: Pasting multiple urls with an almost empty one
+        When I open about:blank
+        And I put "http://localhost:(port)/data/hello.txt\n \nhttp://localhost:(port)/data/hello2.txt" into the clipboard
+        And I run :paste -t
+        Then no crash should happen
+
     #### :paste-primary
 
     Scenario: Pasting the primary selection into an empty text field