brz diff --using does not work with colordiff

When using "brz diff --using=colordiff", I get mangled output. When using "brz diff | colordiff", everything works correctly. So, --using seems to pass the data through in a different format, which colordiff fails to parse correctly:

Mangled output:

> brz diff --using=colordiff
=== modified file 'web/common.py'
25d24
< from web.utils.user_agent import UA_languages
=== modified file 'web/translations/zh/LC_MESSAGES/messages.po'
1016a1017,1035
> #: web/templates/logged_out/install-manually.html:74
> msgid "Do you see an error?"
> msgstr ""
>
> #: web/templates/logged_out/install-manually.html:75
> msgid ""
> "If your version of Chrome is disabling the plugin and showing you a "
> "message similar to the one shown here, you will need to download and "
> "install the alternative version of Kopernio plugin .crx file."
> msgstr ""
>
> #: web/templates/logged_out/install-manually.html:78
> msgid "Download the alternative version"
> msgstr ""
>
> #: web/templates/logged_out/install-manually.html:81
> msgid "Then repeat steps 2 to 5."
> msgstr ""
>
=== removed file 'web/utils/test/test_user_agent.py'
--- old/web/utils/test/test_user_agent.py 2019-08-05 12:49:17 +0000
+++ new/web/utils/test/test_user_agent.py 1970-01-01 00:00:00 +0000
@@ -1,34 +0,0 @@
-import pytest
-
-import web
-from web.utils.user_agent import UA_languages
-
-BASE_CASE = "fr-CH"
-HAS_COMMA = "fr-CH,"
-LIST = "fr-CH, fr-CB"
-
-
-@pytest.fixture()
-def client():
- app = web.app
- app.config["WTF_CSRF_ENABLED"] = False
- app.config["TESTING"] = True
- yield app.test_client()
-
-
-@pytest.mark.parametrize("ua_languages_str", (BASE_CASE, HAS_COMMA, LIST))
-def test_ua_language(client, ua_languages_str):
- app = web.app
- with app.test_request_context("/", headers=[("Accept-Language", ua_languages_str)]):
- client.get()
- assert UA_languages() == ["fr"]
-
-
-def test_ua_multiple_languages_returned(client):
- app = web.app
- ua_languages_str = "fr-CH, zh-TT"
- with app.test_request_context("/", headers=[("Accept-Language", ua_languages_str)]):
- client.get()
- assert "fr" in UA_languages()
- assert "zh" in UA_languages()
- assert "tt" not in UA_languages()

=== removed file 'web/utils/user_agent.py'
--- old/web/utils/user_agent.py 2019-08-05 12:49:17 +0000
+++ new/web/utils/user_agent.py 1970-01-01 00:00:00 +0000
@@ -1,22 +0,0 @@
-from flask import request
-
-
-def UA_languages():
- """
- This returns a list of languages without the locale
- :return: list of strings
- """
-
- # retrieve the languages as a list from the request header
- languages = request.headers.get("Accept-Language", "").lower().split(",")
-
- # remove spaces
- cleaned = list(map(lambda item: item.strip(), languages))
-
- # remove empty list items
- cleaned = [item for item in cleaned if item]
-
- # strip the locale
- cleaned = [language_locale.split("-")[0] for language_locale in cleaned]
-
- return list(set(cleaned))

Correct version:

> brz diff | colordiff
=== modified file 'web/common.py'
--- old/web/common.py 2019-10-03 11:13:31 +0000
+++ new/web/common.py 2019-10-03 11:21:06 +0000
@@ -22,7 +22,6 @@
 from web.settings import CHROME_EXTENSIONID
 from web.utils.ab_test import ABTestView, ABTestCase, abtest_analytics, ab_test, ab_finished
 from web.utils.i18n import get_available_locales
-from web.utils.user_agent import UA_languages

 # Configure babel
 babel = Babel(app)

=== modified file 'web/translations/zh/LC_MESSAGES/messages.po'
--- old/web/translations/zh/LC_MESSAGES/messages.po 2019-09-11 11:03:19 +0000
+++ new/web/translations/zh/LC_MESSAGES/messages.po 2019-10-03 11:15:28 +0000
@@ -1014,6 +1014,25 @@
 msgid "Select your institution and create a free Kopernio account"
 msgstr "选择您的组织机构，创建一个免费的Kopernio帐户吧"

+#: web/templates/logged_out/install-manually.html:74
+msgid "Do you see an error?"
+msgstr ""
+
+#: web/templates/logged_out/install-manually.html:75
+msgid ""
+"If your version of Chrome is disabling the plugin and showing you a "
+"message similar to the one shown here, you will need to download and "
+"install the alternative version of Kopernio plugin .crx file."
+msgstr ""
+
+#: web/templates/logged_out/install-manually.html:78
+msgid "Download the alternative version"
+msgstr ""
+
+#: web/templates/logged_out/install-manually.html:81
+msgid "Then repeat steps 2 to 5."
+msgstr ""
+
 #: web/templates/logged_out/install-manually.html:76
 msgid "Click to see your newly installed Kopernio button in action!"
 msgstr "单击观看新安装的Kopernio按钮发挥作用！"

=== removed file 'web/utils/test/test_user_agent.py'
--- old/web/utils/test/test_user_agent.py 2019-08-05 12:49:17 +0000
+++ new/web/utils/test/test_user_agent.py 1970-01-01 00:00:00 +0000
@@ -1,34 +0,0 @@
-import pytest
-
-import web
-from web.utils.user_agent import UA_languages
-
-BASE_CASE = "fr-CH"
-HAS_COMMA = "fr-CH,"
-LIST = "fr-CH, fr-CB"
-
-
-@pytest.fixture()
-def client():
- app = web.app
- app.config["WTF_CSRF_ENABLED"] = False
- app.config["TESTING"] = True
- yield app.test_client()
-
-
-@pytest.mark.parametrize("ua_languages_str", (BASE_CASE, HAS_COMMA, LIST))
-def test_ua_language(client, ua_languages_str):
- app = web.app
- with app.test_request_context("/", headers=[("Accept-Language", ua_languages_str)]):
- client.get()
- assert UA_languages() == ["fr"]
-
-
-def test_ua_multiple_languages_returned(client):
- app = web.app
- ua_languages_str = "fr-CH, zh-TT"
- with app.test_request_context("/", headers=[("Accept-Language", ua_languages_str)]):
- client.get()
- assert "fr" in UA_languages()
- assert "zh" in UA_languages()
- assert "tt" not in UA_languages()

=== removed file 'web/utils/user_agent.py'
--- old/web/utils/user_agent.py 2019-08-05 12:49:17 +0000
+++ new/web/utils/user_agent.py 1970-01-01 00:00:00 +0000
@@ -1,22 +0,0 @@
-from flask import request
-
-
-def UA_languages():
- """
- This returns a list of languages without the locale
- :return: list of strings
- """
-
- # retrieve the languages as a list from the request header
- languages = request.headers.get("Accept-Language", "").lower().split(",")
-
- # remove spaces
- cleaned = list(map(lambda item: item.strip(), languages))
-
- # remove empty list items
- cleaned = [item for item in cleaned if item]
-
- # strip the locale
- cleaned = [language_locale.split("-")[0] for language_locale in cleaned]
-
- return list(set(cleaned))