On Fri, 28 Jul 2023 12:15:21 GMT, Cristian Vat <d...@openjdk.org> wrote:
>> Reduces excessive allocation of Matcher.groups array when the original
>> Pattern has no groups or less than 9 groups.
>>
>> Original clamping to 10 possibly due to documented behavior from javadoc:
>> "In this class, \1 through \9 are always interpreted as back references, "
>>
>> Only with Matcher changes RegExTest.backRefTest fails when backreferences to
>> non-existing groups are present.
>> Added a match failure condition in Pattern that fixes failing tests.
>>
>> As per existing `java.util.regex.Pattern.BackRef#match`: "// If the
>> referenced group didn't match, neither can this"
>>
>> A group that does not exist in the original Pattern can never match so
>> neither can a backref to that group.
>> If the group existed in the original Pattern then it would have had space
>> allocated in Matcher.groups for that group index.
>> So a group index outside groups array length must never match.
>
> Cristian Vat has updated the pull request incrementally with one additional
> commit since the last revision:
>
> changes and test for CIBackRef
The change looks good.
However, I'm not a Reviewer.
src/java.base/share/classes/java/util/regex/Pattern.java line 5192:
> 5190: // reference to not existing group must never match
> 5191: // group does not exist if matcher didn't allocate space
> for it
> 5192: if (groupIndex + 1 > matcher.groups.length) {
Suggestion:
if (groupIndex >= matcher.groups.length) {
src/java.base/share/classes/java/util/regex/Pattern.java line 5234:
> 5232: // reference to not existing group must never match
> 5233: // group does not exist if matcher didn't allocate space
> for it
> 5234: if (groupIndex + 1 > matcher.groups.length) {
Suggestion:
if (groupIndex >= matcher.groups.length) {
-------------
PR Review: https://git.openjdk.org/jdk/pull/14894#pullrequestreview-1560992171
PR Review Comment: https://git.openjdk.org/jdk/pull/14894#discussion_r1283135433
PR Review Comment: https://git.openjdk.org/jdk/pull/14894#discussion_r1283135831
