Quote tags to avoid history expansion

Tags may contain an exclamation mark, which the shell will treat as a
request for history expansion.

Author: tautschnig

unit/Makefile

@@ -320,7 +320,7 @@ test: $(CATCH_TEST)
 	# Include hidden tests by specifying "*,[.]" for tests to count
 	if ! ./$(CATCH_TEST) "*,[.]" -l | grep -q "^$(N_CATCH_TESTS) matching test cases" ; then \
 		./$(CATCH_TEST) "*,[.]" -l ; fi
-	./$(CATCH_TEST) ${TAGS}
+	./$(CATCH_TEST) '${TAGS}'
 
 
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