Make SegmentInfos#readCommit(Directory, String, int) public (#14027)

The corresponding readLatestCommit method is public and can be used to
read segment infos from indices that are older than N - 1.
The same should be possible for readCommit, but that requires the method
that takes the minimum supported version as an argument to be public.

lucene/CHANGES.txt

@@ -106,6 +106,8 @@ Bug Fixes
 * GITHUB#13990: Added filter to the toString() method of Knn[Float|Byte]VectorQuery
   and DiversifyingChildren[Float|Byte]KnnVectorQuery. (Viswanath Kuchibhotla)
 
+* GITHUB#14027: Make SegmentInfos#readCommit(Directory, String, int) public
+
 Build
 ---------------------
 

lucene/core/src/java/org/apache/lucene/index/SegmentInfos.java

@@ -284,7 +284,14 @@ public final class SegmentInfos implements Cloneable, Iterable<SegmentCommitInfo
     return readCommit(directory, segmentFileName, Version.MIN_SUPPORTED_MAJOR);
   }
 
-  static final SegmentInfos readCommit(
+  /**
+   * Read a particular segmentFileName, as long as the commit's {@link
+   * SegmentInfos#getIndexCreatedVersionMajor()} is strictly greater than the provided minimum
+   * supported major version. If the commit's version is older, an {@link
+   * IndexFormatTooOldException} will be thrown. Note that this may throw an IOException if a commit
+   * is in process.
+   */
+  public static final SegmentInfos readCommit(
       Directory directory, String segmentFileName, int minSupportedMajorVersion)
       throws IOException {
 
@@ -307,7 +314,7 @@ public final class SegmentInfos implements Cloneable, Iterable<SegmentCommitInfo
   }
 
   /** Read the commit from the provided {@link ChecksumIndexInput}. */
-  static final SegmentInfos readCommit(
+  public static final SegmentInfos readCommit(
       Directory directory, ChecksumIndexInput input, long generation, int minSupportedMajorVersion)
       throws IOException {
     Throwable priorE = null;