[LUCENE-9339] Only call MergeScheduler when we actually found new merges

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 9.0, 8.6
• Fix Version/s: 9.0, 8.6
• Lucene Fields: New, Patch Available
• Assignee: Simon Willnauer
• Reporter: Simon Willnauer
• Created: 22/Apr/20 12:47
• Updated: 15/Jul/20 15:09
• Resolved: 22/Apr/20 19:30

Description

IW#maybeMerge calls the MergeScheduler even if it didn't find any merges we should instead only do this if there is in-fact anything there to merge and safe the call into a sync'd method. In addition to this we never respect the newMergesFound parameter. It seems unnecessary and can be removed.