fix(semver): stop classical pattern matching 6+ digit versions

The regex crate parses PCRE's possessive \d{1,5}+ as a stacked
repetition (?:\d{1,5})+, i.e. \d+, so date versions like 20121020
matched the classical pattern and normalized to 20121020.0.0.0 instead
of falling through to the date(time) pattern like PHP. The plain
\d{1,5} is equivalent to the possessive form here per the
regex-porting rules. Un-ignore test_find_recommended_require_version
which this had blocked.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/crates/shirabe-semver/src/version_parser.rs b/crates/shirabe-semver/src/version_parser.rs
index c27f7819..287716d9 100644
--- a/crates/shirabe-semver/src/version_parser.rs
+++ b/crates/shirabe-semver/src/version_parser.rs
@@ -128,8 +128,13 @@ impl VersionParser {
         let mut matches: Vec<Option<String>> = Vec::new();
 
         // match classical versioning
+        // Regex pattern compatibility:
+        // PCRE's possessive `\d{1,5}+` is parsed by the `regex` crate as a stacked
+        // repetition `(?:\d{1,5})+` (i.e. `\d+`), which wrongly let 6+ digit numbers
+        // (e.g. date versions like 20121020) match here. The plain `\d{1,5}` is
+        // equivalent to the possessive form for this pattern.
         let classical_pattern = format!(
-            "{{^v?(\\d{{1,5}}+)(\\.\\d++)?(\\.\\d++)?(\\.\\d++)?{}$}}i",
+            "{{^v?(\\d{{1,5}})(\\.\\d++)?(\\.\\d++)?(\\.\\d++)?{}$}}i",
             MODIFIER_REGEX
         );
         if shirabe_php_shim::preg_match(&classical_pattern, &version, &mut matches) {