Fix edge case in code audit when there is a - in the src path

lib/include/audit_code.sh

@@ -53,7 +53,15 @@ function _get_grep_context() {
 	#  given a matches line from grep -B output
 	#  it will return - or : depeding if its the
 	#  context or actual match
-	[[ "$1" =~ [^a-zA-Z0-9/.] ]] && printf '%s' "${BASH_REMATCH[0]}"
+	local line="$1"
+
+	# skip to the file extension
+	# we need to do this because the file path
+	# could already contain ":" or more likely "-"
+	line="$(printf '%s' "$line" | grep -Eo '(\.(cpp|h|c).*)')"
+
+	# then match the first character after the digit
+	[[ "$line" =~ [^a-zA-Z0-9/.] ]] && printf '%s' "${BASH_REMATCH[0]}"
 }
 
 function _chop_grep_line() {

lib/test/unit/audit_code.sh

@@ -32,6 +32,9 @@ else
 	echo "OK"
 fi
 
+assert_eq "$(_get_grep_context 'src/external/DDNetPP-bots/src/twbl/teeworlds/base/system.cpp:6: * @ingroup Filesystem')" ":" "detect correct grep context :"
+assert_eq "$(_get_grep_context 'src/external/DDNetPP-bots/src/twbl/teeworlds/base/system.cpp-5- *')" "-" "detect correct grep context -"
+
 log -n "audit_code.sh [_chop_grep_line ':'] ... "
 
 if ! diff <(_chop_grep_line 'src/game/client/gameclient.cpp:580: // render all systems') \