From 19a552f1e0eadec5c5f0cb5e3deea86a190926be Mon Sep 17 00:00:00 2001
From: Marco Weber <marco.weber@hotmail.de>
Date: Fri, 27 Aug 2021 22:57:07 +0200
Subject: [PATCH 1/2] Fix handling of substitution defaults containing colon

* Join remaining parts of string instead of splitting on colon.
* Add test with substitution default that contains a colon (URL).

Fixes #2182

Signed-off-by: Marco Weber <marco.weber@hotmail.de>
---
 src/tox/config/loader/ini/replace.py                    | 2 +-
 tests/config/loader/ini/replace/test_replace_env_var.py | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/tox/config/loader/ini/replace.py b/src/tox/config/loader/ini/replace.py
index ca8c4a32c..b2735c582 100644
--- a/src/tox/config/loader/ini/replace.py
+++ b/src/tox/config/loader/ini/replace.py
@@ -207,7 +207,7 @@ def replace_env(conf: "Config", env_name: Optional[str], args: List[str], chain:
     if key in os.environ:
         return os.environ[key]
 
-    return "" if len(args) == 1 else args[1]
+    return "" if len(args) == 1 else ":".join(args[1:])
 
 
 def replace_tty(args: List[str]) -> str:
diff --git a/tests/config/loader/ini/replace/test_replace_env_var.py b/tests/config/loader/ini/replace/test_replace_env_var.py
index 3a298d79c..1ce8fc1c4 100644
--- a/tests/config/loader/ini/replace/test_replace_env_var.py
+++ b/tests/config/loader/ini/replace/test_replace_env_var.py
@@ -36,3 +36,10 @@ def test_replace_env_var_circular(replace_one: ReplaceOne, monkeypatch: MonkeyPa
     monkeypatch.setenv("MAGIC", "{env:MAGIC}")
     result = replace_one("{env:MAGIC}")
     assert result == "{env:MAGIC}"
+
+
+def test_replace_env_default_with_colon(replace_one: ReplaceOne, monkeypatch: MonkeyPatch) -> None:
+    """If we have a factor that is not specified within the core env-list then that's also an environment"""
+    monkeypatch.delenv("MAGIC", raising=False)
+    result = replace_one("{env:MAGIC:https://some.url.org}")
+    assert result == "https://some.url.org"

From 1cc93d2c0d2187b09da51265434b1f1426588ad7 Mon Sep 17 00:00:00 2001
From: Marco Weber <marco.weber@hotmail.de>
Date: Sat, 28 Aug 2021 00:13:11 +0200
Subject: [PATCH 2/2] Add changelog entry

---
 docs/changelog/2182.bugfix.rst | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 docs/changelog/2182.bugfix.rst

diff --git a/docs/changelog/2182.bugfix.rst b/docs/changelog/2182.bugfix.rst
new file mode 100644
index 000000000..a78577254
--- /dev/null
+++ b/docs/changelog/2182.bugfix.rst
@@ -0,0 +1 @@
+Fix env variable substitutions with defaults containing colon (e.g. URL) -- by :user:`comabrewer`.