fixes to CI workflow to detect malicious unicode

 * #90
 * maltfield/detect-malicious-unicode#4

.github/workflows/unicode_warn.yml

@@ -1,6 +1,6 @@
 ################################################################################
 # File:    .github/workflows/unicode_warn.yml
-# Version: 0.3
+# Version: 0.4
 # Purpose: Detects Unicode in PRs and comments the results of findings in PR
 # Authors: Michael Altfield <michael@michaelaltfield.net>
 # Created: 2021-11-20
@@ -26,6 +26,11 @@ jobs:
       pull-requests: write
 
     steps:
+
+    - name: Dump GitHub context
+      env:
+        GITHUB_CONTEXT: ${{ toJSON(github) }}
+      run: echo "$GITHUB_CONTEXT"
 
     - name: Prereqs
       env:
@@ -45,11 +50,15 @@ jobs:
         git config --global --add safe.directory "$(pwd)"
         git branch -a
         git log
+        git checkout ${{ github.event.pull_request.head.ref }}
+        git branch -a
+        git log
 
         diff=`git diff --unified=0 ${{ github.event.pull_request.base.sha }} ${{ github.event.pull_request.head.sha }} | grep -E "^[+]" | grep -Ev '^(--- a/|\+\+\+ b/)'`
         if [ $? -ne 0 ]; then
           # there was an error in the diff
           human_result="WARNING: git diff failed!"
+          echo "UNICODE_HUMAN_RESULT=${human_result}" >> $GITHUB_ENV
           echo "${human_result}"
           exit 1
         fi
@@ -62,6 +71,7 @@ jobs:
         if [ $? -ne 0 ]; then
           # there was an error in the hexdump
           human_result="WARNING: hexdump failed!"
+          echo "UNICODE_HUMAN_RESULT=${human_result}" >> $GITHUB_ENV
           echo "${human_result}"
           exit 1
         fi
@@ -106,7 +116,7 @@ jobs:
     - name: Exit with or without error
       run: |
 
-        if [[ "${{ env.UNICODE_HUMAN_RESULT }}" | grep -i "WARNING" ]]; then
+        if [[ "${{ env.UNICODE_HUMAN_RESULT }}" | grep -Ei "ERROR|WARNING" ]]; then
           exit 1
         else
           exit 0