Merge pull request #133 from github/ci/pr-129

Replicate work in PR #129 - fix panic in parseWith

Author: elrayle

spdxexp/parse.go

@@ -380,7 +380,7 @@ func (t *tokenStream) parseWith() *string {
 	}
 
 	token := t.peek()
-	if token.role != exceptionToken {
+	if token == nil || token.role != exceptionToken {
 		t.err = errors.New("expected exception after 'WITH'")
 		return nil
 	}

spdxexp/parse_test.go

@@ -1246,6 +1246,7 @@ func TestParseWith(t *testing.T) {
 		{"WITH followed by EXCEPTION", getWithClauseTokens(1), "Bison-exception-2.2", false, 2, nil},
 		{"WITH not followed by EXCEPTION", getInvalidWithClauseTokens(1), "", true, 2, errors.New("expected exception after 'WITH'")},
 		{"not with", getOrClauseTokens(1), "", true, 1, nil},
+		{"WITH not followed by any tokens", getMalformedWithClauseTokens(1), "", true, 2, errors.New("expected exception after 'WITH'")},
 	}
 
 	for _, test := range tests {
@@ -1292,6 +1293,13 @@ func getInvalidWithClauseTokens(index int) *tokenStream {
 	return getTokenStream(tokens, index)
 }
 
+func getMalformedWithClauseTokens(index int) *tokenStream {
+	var tokens []token
+	tokens = append(tokens, token{role: licenseToken, value: "Apache-2.0"})
+	tokens = append(tokens, token{role: operatorToken, value: "WITH"})
+	return getTokenStream(tokens, index)
+}
+
 func getAndClauseTokens(index int) *tokenStream {
 	var tokens []token
 	tokens = append(tokens, token{role: licenseToken, value: "MIT"})