From 8628efa0a1437534292ea796dc6d6806395e520a Mon Sep 17 00:00:00 2001
From: Athanasius <Athanasius@miggy.org>
Date: Sat, 3 Dec 2022 12:40:33 +0000
Subject: [PATCH] github/pr-/push-checks: Attempt non-diff flake8 checks

* flake8 6.0.0 dropped support for, the broken, --diff.
* We want to only run against python files.  We will have 'git diff's for
  other types of files.
* Uses 'git diff -z', 'grep -z -Z' and 'xargs -0' so as to pass NUL-terminated
  strings around to avoid "special characters in path/filenames" issues.
---
 .github/workflows/pr-checks.yml   |  8 ++++++--
 .github/workflows/push-checks.yml | 17 +++++++++++++++--
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/pr-checks.yml b/.github/workflows/pr-checks.yml
index e90929bb..70c8dad1 100644
--- a/.github/workflows/pr-checks.yml
+++ b/.github/workflows/pr-checks.yml
@@ -85,11 +85,15 @@ jobs:
         # F63 - 'tests' checking
         # F7 - syntax errors
         # F82 - undefined checking
-        git diff "refs/remotes/${BASE_REPO_OWNER}/${BASE_REF}" -- | flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics --diff
+        echo git diff --name-only --diff-filter=d -z "refs/remotes/${BASE_REPO_OWNER}/${BASE_REF}" -- | \
+          grep -E -z -Z '\.py$' | \
+          xargs -0 flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
         # Can optionally add `--exit-zero` to the flake8 arguments so that
         # this doesn't fail the build.
         # explicitly ignore docstring errors (start with D)
-        git diff "refs/remotes/${BASE_REPO_OWNER}/${BASE_REF}" -- | flake8 . --count --statistics --diff --extend-ignore D
+        git diff --name-only --diff-filter=d -z "refs/remotes/${BASE_REPO_OWNER}/${BASE_REF}" -- | \
+          grep -E -z -Z '\.py$' | \
+          xargs -0 flake8 . --count --statistics --extend-ignore D
     ####################################################################
 
     ####################################################################
diff --git a/.github/workflows/push-checks.yml b/.github/workflows/push-checks.yml
index b6994b02..a11234ed 100644
--- a/.github/workflows/push-checks.yml
+++ b/.github/workflows/push-checks.yml
@@ -40,7 +40,20 @@ jobs:
         DATA=$(jq --raw-output .before $GITHUB_EVENT_PATH)
 
         echo "DATA: ${DATA}"
+        #######################################################################
         # stop the build if there are Python syntax errors or undefined names, ignore existing 
-        git diff "$DATA" | flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics --diff
+        #######################################################################
+        # We need to get just the *filenames* of only *python* files changed.
+        # Using various -z/-Z/-0 to utilise NUL-terminated strings.
+        git diff --name-only --diff-filter=d -z "$DATA" | \
+          grep -E -z -Z '\.py$' | \
+          xargs -0 flake8 --count --select=E9,F63,F7,F82 --show-source --statistics
+        #######################################################################
+          
+        #######################################################################
         # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
-        git diff "$DATA" | flake8 . --count --statistics --diff
+        #######################################################################
+        git diff --name-only --diff-filter=d -z "$DATA" | \
+          grep -E -z -Z '\.py$' | \
+          xargs -0 flake8 . --count --statistics
+        #######################################################################