feat: [BT-11220]: Detect git diff file (#3617)

.engops/pr_source_code_changes.sh

@@ -52,6 +52,13 @@ if [ ! -f "$sourceDiffNames" ]; then
   exit 4
 fi
 
+##### Detect git diff file, or processed filenames only
+isDiffFile=$(grep -E "^diff --git a\/" "$uniqueFileNamesFile" | wc -l)
+if [ $isDiffFile -gt 0 ]; then
+  echo "Received a diff file... fix it to be a filenames only file"
+  fileNamesOnlyVar=$(cat "$uniqueFileNamesFile"|grep -E "^diff --git" | sed 's/diff --git a\///' | sed 's/ b\/.*$//' | sort -u)
+  echo -e "$fileNamesOnlyVar">"$uniqueFileNamesFile"
+fi
 
 # Java files (and other files) which end up in jars - these are kept in .../src/main/x/x/x/* 
 cat "$uniqueFileNamesFile" | grep -E ".*.java$" | grep -v "/test/" > $sourceDiffNames