Allows to paste multiple URLs

- The paste command will now open one tab/window per url if multiple
  URLs (separated by newline) are present in the clipboard
- Adds the tests for the new multitab functionality
- Changes test/integration/conftest.py to be able to insert newlines in
  the clipboard for the test

qutebrowser/browser/commands.py

@@ -825,12 +825,18 @@ class CommandDispatcher:
         text = clipboard.text(mode)
         if not text:
             raise cmdexc.CommandError("{} is empty.".format(target))
-        log.misc.debug("{} contained: '{}'".format(target, text))
-        try:
-            url = urlutils.fuzzy_url(text)
-        except urlutils.InvalidUrlError as e:
-            raise cmdexc.CommandError(e)
-        self._open(url, tab, bg, window)
+        log.misc.debug("{} contained: '{}'".format(target,
+                                                   text.replace('\n', '\\n')))
+        text_urls = enumerate([u for u in text.split('\n') if u != ''])
+        for i, text_url in text_urls:
+            if not window and i > 0:
+                tab = False
+                bg = True
+            try:
+                url = urlutils.fuzzy_url(text_url)
+            except urlutils.InvalidUrlError as e:
+                raise cmdexc.CommandError(e)
+            self._open(url, tab, bg, window)
 
     @cmdutils.register(instance='command-dispatcher', scope='window',
                        count='count')

tests/integration/features/conftest.py

@@ -199,6 +199,7 @@ 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('\\n', '\n')
 
     clipboard = qapp.clipboard()
     with qtbot.waitSignal(clipboard.changed):

tests/integration/features/yankpaste.feature

@@ -104,3 +104,62 @@ Feature: Yanking and pasting.
         And I put "foo bar" into the clipboard
         And I run :paste
         Then the error "Invalid URL" should be shown
+
+    Scenario: Pasting multiple urls in a new tab
+        Given I have a fresh instance
+        When I run :tab-only
+        And I put "http://localhost:(port)/data/hello.txt\nhttp://localhost:(port)/data/hello2.txt\nhttp://localhost:(port)/data/hello3.txt" into the clipboard
+        And I run :paste -t
+        And I wait until data/hello.txt is loaded
+        And I wait until data/hello2.txt is loaded
+        And I wait until data/hello3.txt is loaded
+        Then the following tabs should be open:
+            - about:blank
+            - data/hello.txt (active)
+            - data/hello2.txt
+            - data/hello3.txt
+
+    Scenario: Pasting multiple urls in a background tab
+        Given I open about:blank
+        When I run :tab-only
+        And I put "http://localhost:(port)/data/hello.txt\nhttp://localhost:(port)/data/hello2.txt\nhttp://localhost:(port)/data/hello3.txt" into the clipboard
+        And I run :paste -b
+        And I wait until data/hello.txt is loaded
+        And I wait until data/hello2.txt is loaded
+        And I wait until data/hello3.txt is loaded
+        Then the following tabs should be open:
+            - about:blank (active)
+            - data/hello.txt
+            - data/hello2.txt
+            - data/hello3.txt
+
+    Scenario: Pasting multiple urls in new windows
+        Given I have a fresh instance
+        When I put "http://localhost:(port)/data/hello.txt\nhttp://localhost:(port)/data/hello2.txt\nhttp://localhost:(port)/data/hello3.txt" into the clipboard
+        And I run :paste -w
+        And I wait until data/hello.txt is loaded
+        And I wait until data/hello2.txt is loaded
+        And I wait until data/hello3.txt is loaded
+        Then the session should look like:
+            windows:
+            - tabs:
+              - active: true
+                history:
+                - active: true
+                  url: about:blank
+            - tabs:
+              - active: true
+                history:
+                - active: true
+                  url: http://localhost:*/data/hello.txt
+            - tabs:
+              - active: true
+                history:
+                - active: true
+                  url: http://localhost:*/data/hello2.txt
+            - tabs:
+              - active: true
+                history:
+                - active: true
+                  url: http://localhost:*/data/hello3.txt
+