fix: AnalysisResult::snapshot crash

AnalysisResult::snapshot assumed that the AnalysisResult always has a TotalNumberOfCommitsResult but this was only the case if the result was created by an Analysis. Now, every AnalysisResult will have the commits, and the snapshot method will not crash in case the commits are missing later on.

Author: pmbittner

src/main/java/org/variantsync/diffdetective/analysis/Analysis.java

@@ -472,7 +472,6 @@ public Analysis(
 
         this.result = new AnalysisResult(repository.getRepositoryName());
         this.result.taskName = taskName;
-        this.result.append(TotalNumberOfCommitsResult.KEY, new TotalNumberOfCommitsResult());
 
         for (var hook : hooks) {
             hook.initializeResults(this);

src/main/java/org/variantsync/diffdetective/analysis/AnalysisResult.java

@@ -120,6 +120,8 @@ public AnalysisResult() {
      */
     public AnalysisResult(final String repoName) {
         this.repoName = repoName;
+        // All analyses count the number of processed commits.
+        this.append(Analysis.TotalNumberOfCommitsResult.KEY, new Analysis.TotalNumberOfCommitsResult());
     }
 
     /**
@@ -140,7 +142,7 @@ public LinkedHashMap<String, Object> snapshot() {
 
         var statistics = get(StatisticsAnalysis.RESULT);
         var globals    = get(Analysis.TotalNumberOfCommitsResult.KEY);
-        if (statistics != null) {
+        if (statistics != null && globals != null) {
             snap.put(MetadataKeys.FILTERED_COMMITS, globals.value - statistics.processedCommits - statistics.emptyCommits - statistics.failedCommits);
         }