gnu: python-pydot: Update to 1.4.2.

* gnu/packages/graphviz.scm (python-pydot): Update to 1.4.2.
[source](patches): Remove.
* gnu/packages/patches/python-pydot-regression-test.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.

gnu/local.mk

@@ -1711,7 +1711,6 @@ dist_patch_DATA =						\
   %D%/packages/patches/python-pycrypto-time-clock.patch		\
   %D%/packages/patches/python-pyan3-fix-absolute-path-bug.patch \
   %D%/packages/patches/python-pyan3-fix-positional-arguments.patch \
-  %D%/packages/patches/python-pydot-regression-test.patch	\
   %D%/packages/patches/python2-pygobject-2-deprecation.patch	\
   %D%/packages/patches/python-pygpgme-fix-pinentry-tests.patch	\
   %D%/packages/patches/python-pytest-asyncio-python-3.8.patch	\

gnu/packages/graphviz.scm

@@ -370,15 +370,14 @@ (define-public xdot
 (define-public python-pydot
   (package
     (name "python-pydot")
-    (version "1.4.1")
+    (version "1.4.2")
     (source
      (origin
        (method url-fetch)
        (uri (pypi-uri "pydot" version))
        (sha256
         (base32
-         "00az4cbf8bv447lkk9xi6pjm7gcc7ia33y4pm71fwfwis56rv76l"))
-       (patches (search-patches "python-pydot-regression-test.patch"))))
+         "0z80zwldf7ffkwrpm28hixsiqp3053j7g281xd6phmnbkfiq3014"))))
     (build-system python-build-system)
     (arguments
      '(#:phases
@@ -389,8 +388,7 @@ (define-public python-pydot
              (when tests?
                (add-installed-pythonpath inputs outputs)
                (with-directory-excursion "test"
-                 (invoke "python" "pydot_unittest.py")))
-             #t)))))
+                 (invoke "python" "pydot_unittest.py"))))))))
     (native-inputs
      ;; For tests.
      (list graphviz python-chardet))

gnu/packages/patches/python-pydot-regression-test.patch

@@ -1,79 +0,0 @@
-This patch is taken from the upstream repository
-https://github.com/pydot/pydot/commit/a10ced4d132361027a545a471af4541dea8c5cf5.patch
-It should be included in the 1.4.2 release.
-
-
-From a10ced4d132361027a545a471af4541dea8c5cf5 Mon Sep 17 00:00:00 2001
-From: Peter Nowee <peter@peternowee.com>
-Date: Wed, 26 Jun 2019 15:43:38 +0800
-Subject: [PATCH] Fix multi.dot Graphviz regression test
-
-Commit d6602ad of 2018-12-01 fixed the regression test broken by commit
-2d55978 of 2016-07-01. This revealed that `test/graphs/multi.dot` was
-failing.
-
-`multi.dot` was introduced in commit 2b3f088 of 2010-11-07 together
-with many of the other tests still here today. It has not been touched
-since. It is a DOT-file containing two digraphs. The regression test
-compares the JPEG images rendered from the DOT-file by pydot with those
-rendered by Graphviz's dot directly.
-
-Commit 66734d2 of 2016-07-01 is the actual cause of the failure. It
-changed one of the render methods of the regression test,
-`_render_with_pydot`, from calculating a single hash for all the JPEG
-images to calculating separate hashes for each JPEG image and then
-concatenating those hashes in one long string. The other render method,
-`_render_with_graphviz`, still calculates a single hash over all data.
-For DOT-files that generate only one image the end result is the same,
-but because `multi.dot` has two graphs, it produces two images and this
-leads to comparing a string of two hashes with one single hash.
-
-I do not think the change in generating the hash was intentional, for
-the following reasons:
-- Commit 66734d2 states that its purpose was to adapt the test to an
-  API change in pydot. It does not mention a deliberate choice to
-  change the testing method.
-- There was no effort to change `_render_with_graphviz` to also produce
-  multiple hashes.
-- Except for easier debugging in case of a failing test with multiple
-  images (AFAICT, only `multi.dot`), I do not see much added benefit in
-  checking a concatenation of the hashes of all images vs. checking one
-  hash of all images together: In both cases the test will fail if one
-  or more images is rendered differently.
-- Given that there were many commits authored that same hour, including
-  commit 2d55978 which broke the regression tests, I suspect the author
-  did not run the tests for each individual commit, but only at the end
-  of that batch, and was therefore also not alerted of this change by
-  the test suite.
-
-Assuming that the change was not intended, this commit will now revert
-`_render_with_pydot` to the old behavior of calculating a single hash
-from all JPEG image data.
-
-Tested with Debian 9.9, Graphviz 2.38.0-17, Python 2.7.13-2 and 3.5.3-1.
-
-Fixes https://github.com/pydot/pydot/issues/204.
----
- test/pydot_unittest.py | 8 ++++----
- 1 file changed, 4 insertions(+), 4 deletions(-)
-
-diff --git a/test/pydot_unittest.py b/test/pydot_unittest.py
-index 881ee16..64aa856 100644
---- a/test/pydot_unittest.py
-+++ b/test/pydot_unittest.py
-@@ -194,11 +194,11 @@ def _render_with_graphviz(self, filename, encoding):
- 
-     def _render_with_pydot(self, filename, encoding):
-         c = pydot.graph_from_dot_file(filename, encoding=encoding)
--        sha = ''
-+        jpe_data = bytearray()
-         for g in c:
--            jpe_data = g.create(prog=TEST_PROGRAM, format='jpe', encoding=encoding)
--            sha += sha256(jpe_data).hexdigest()
--        return sha
-+            jpe_data.extend(g.create(prog=TEST_PROGRAM, format='jpe',
-+                                     encoding=encoding))
-+        return sha256(jpe_data).hexdigest()
- 
-     def test_my_regression_tests(self):
-         path = os.path.join(test_dir, TESTS_DIR_1)