Fix version check for alpha3

CHANGELOG.md

@@ -51,6 +51,7 @@ Note that this project **does not** adhere to [Semantic Versioning](https://semv
 - We fixed an issue where bibliography entries generated from CSL styles had leading spaces. [#13074](https://github.com/JabRef/jabref/pull/13074)
 - We fixed an issue where the preview area in the "Select Style" dialog of the LibreOffice integration was too small to display full content. [#13051](https://github.com/JabRef/jabref/issues/13051)
 - We fixed an issue where the tab showing the fulltext search results was not displayed. [#12865](https://github.com/JabRef/jabref/issues/12865)
+- We fixed an issue where the Version checker did not correctly recognize the newer alpha versions. [#13242](https://github.com/JabRef/jabref/pull/13242)
 
 ### Removed
 

jablib/src/main/java/org/jabref/logic/util/Version.java

@@ -25,7 +25,7 @@ public class Version {
 
     private static final Version UNKNOWN_VERSION = new Version();
 
-    private final static Pattern VERSION_PATTERN = Pattern.compile("(?<major>\\d+)(\\.(?<minor>\\d+))?(\\.(?<patch>\\d+))?(?<stage>-alpha|-beta)?(?<num>\\d+)?(?<dev>-?dev)?.*");
+    private final static Pattern VERSION_PATTERN = Pattern.compile("(?<major>\\d+)(\\.(?<minor>\\d+))?(\\.(?<patch>\\d+))?(?<stage>-alpha|-beta)?(\\.|)(?<num>\\d+)?(?<dev>-?dev)?.*");
     private final static Pattern CI_SUFFIX_PATTERN = Pattern.compile("-ci\\.\\d+");
 
     private static final String JABREF_GITHUB_RELEASES = "https://api.github.com/repos/JabRef/JabRef/releases";

jablib/src/test/java/org/jabref/logic/util/VersionTest.java

@@ -306,6 +306,13 @@ void stableShouldNotBeUpdatedToBeta() {
         assertFalse(stable.shouldBeUpdatedTo(beta));
     }
 
+    @Test
+    void alpha3IsNewerThanAlpha2WithoutDot() {
+        Version alphaNewer = Version.parse("6.0-alpha.3-2025-04-27--c52dc44");
+        Version alphaNotNewer = Version.parse("6.0-alpha2");
+        assertTrue(alphaNewer.isNewerThan(alphaNotNewer));
+    }
+
     @Test
     void alphaShouldBeUpdatedToStables() {
         Version alpha = Version.parse("2.8-alpha");