From 374e6b85df6e4e695598635c9230445ccea4be0c Mon Sep 17 00:00:00 2001
From: Sebastian Bank <sebastian.bank@uni-leipzig.de>
Date: Tue, 6 Oct 2020 21:07:25 +0200
Subject: [PATCH] adapt version() for development version format in Graphviz
 2.44.2

---
 CHANGES.txt           |  3 +++
 graphviz/backend.py   | 20 ++++++++++++++++++--
 tests/test_backend.py |  2 ++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index d2a1dafdfd..f1b8085d0c 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -5,6 +5,9 @@ Changelog
 Version 0.14.2 (in development)
 -------------------------------
 
+Adapt `graphviz.version()` to support the Graphviz Release version entry format
+introduced with `2.44.2` (`version()` is needed to run the tests).
+
 Drop Python 3.5 support.
 
 
diff --git a/graphviz/backend.py b/graphviz/backend.py
index 49f79154da..a62ac67dba 100644
--- a/graphviz/backend.py
+++ b/graphviz/backend.py
@@ -254,17 +254,33 @@ def version():
         graphviz.ExecutableNotFound: If the Graphviz executable is not found.
         subprocess.CalledProcessError: If the exit status is non-zero.
         RuntimmeError: If the output cannot be parsed into a version number.
+
+    Note:
+        Ignores the ``~dev.<YYYYmmdd.HHMM>`` portion of development versions.
+
+    See also Graphviz Release version entry format:
+    https://gitlab.com/graphviz/graphviz/-/blob/f94e91ba819cef51a4b9dcb2d76153684d06a913/gen_version.py#L17-20
     """
     cmd = ['dot', '-V']
     out, _ = run(cmd, check=True, encoding='ascii',
                  stdout=subprocess.PIPE,
                  stderr=subprocess.STDOUT)
 
-    ma = re.search(r'graphviz version (\d+\.\d+(?:\.\d+){,2})', out)
+    ma = re.search(r'graphviz version'
+                   r' '
+                   r'(\d+)\.(\d+)'
+                   r'(?:\.(\d+)'
+                       r'(?:'
+                           r'~dev\.\d{8}\.\d{4}'
+                           r'|'
+                           r'\.(\d+)'
+                       r')?'
+                   r')?'
+                   r' ', out)
     if ma is None:
         raise RuntimeError('cannot parse %r output: %r' % (cmd, out))
 
-    return tuple(int(d) for d in ma.group(1).split('.'))
+    return tuple(int(d) for d in ma.groups() if d is not None)
 
 
 def view(filepath, quiet=False):
diff --git a/tests/test_backend.py b/tests/test_backend.py
index b2dfe44e9d..d1bb359cac 100644
--- a/tests/test_backend.py
+++ b/tests/test_backend.py
@@ -262,6 +262,8 @@ def test_version_parsefail_mocked(mocker, Popen):  # noqa: N803
     (b'dot - graphviz version 1.2.3 (mocked)', (1, 2, 3)),
     (b'dot - graphviz version 2.43.20190912.0211 (20190912.0211)\n', (2, 43, 20190912, 211)),
     (b'dot - graphviz version 2.44.2~dev.20200927.0217 (20200927.0217)\n', (2, 44, 2)),
+    (b'dot - graphviz version 2.44.1 (mocked)\n', (2, 44, 1)),
+    (b'dot - graphviz version 2.44.2~dev.20200704.1652 (mocked)\n', (2, 44, 2)),
 ])
 def test_version_mocked(mocker, Popen, stdout, expected):  # noqa: N803
     proc = Popen.return_value