SONAR-16594 Quality Gate changes on same code on reference branch strategy

- fixes also analysis warning to be shown in UI

3 files changed, 28 insertions, 4 deletions

diff --git a/server/sonar-ce-task-projectanalysis/src/main/java/org/sonar/ce/task/projectanalysis/scm/ScmInfoDbLoader.java b/server/sonar-ce-task-projectanalysis/src/main/java/org/sonar/ce/task/projectanalysis/scm/ScmInfoDbLoader.java
index 254cffdcc97..fc35319a17f 100644
--- a/server/sonar-ce-task-projectanalysis/src/main/java/org/sonar/ce/task/projectanalysis/scm/ScmInfoDbLoader.java
+++ b/server/sonar-ce-task-projectanalysis/src/main/java/org/sonar/ce/task/projectanalysis/scm/ScmInfoDbLoader.java
@@ -83,7 +83,12 @@ public class ScmInfoDbLoader {
     }
 
     if (isReferenceBranch()) {
-      return Optional.ofNullable(newCodeReferenceBranchComponentUuids.getComponentUuid(file.getDbKey()));
+      var referencedBranchComponentUuid = newCodeReferenceBranchComponentUuids.getComponentUuid(file.getDbKey());
+      if (referencedBranchComponentUuid != null) {
+        return Optional.of(referencedBranchComponentUuid);
+      }
+      // no file to diff was found or missing reference branch changeset - use existing file
+      return Optional.of(file.getUuid());
     }
 
     // at this point, it's the first analysis of a branch with copyFromPrevious flag true or any analysis of a PR
diff --git a/server/sonar-ce-task-projectanalysis/src/test/java/org/sonar/ce/task/projectanalysis/scm/ScmInfoDbLoaderTest.java b/server/sonar-ce-task-projectanalysis/src/test/java/org/sonar/ce/task/projectanalysis/scm/ScmInfoDbLoaderTest.java
index fdd502b82fb..12a2ac8948c 100644
--- a/server/sonar-ce-task-projectanalysis/src/test/java/org/sonar/ce/task/projectanalysis/scm/ScmInfoDbLoaderTest.java
+++ b/server/sonar-ce-task-projectanalysis/src/test/java/org/sonar/ce/task/projectanalysis/scm/ScmInfoDbLoaderTest.java
@@ -162,6 +162,25 @@ public class ScmInfoDbLoaderTest {
   }
 
   @Test
+  public void read_from_db_if_not_exist_in_reference_branch() {
+    periodHolder.setPeriod(new Period(NewCodePeriodType.REFERENCE_BRANCH.name(), null, null));
+
+    Branch branch = mock(Branch.class);
+    when(branch.getType()).thenReturn(BranchType.BRANCH);
+    analysisMetadataHolder.setBaseAnalysis(null);
+    analysisMetadataHolder.setBranch(branch);
+
+    String hash = computeSourceHash(1);
+
+    addFileSourceInDb("henry", DATE_1, "rev-1", hash, FILE.getUuid());
+
+    DbScmInfo scmInfo = underTest.getScmInfo(FILE).get();
+    assertThat(scmInfo.getAllChangesets()).hasSize(1);
+    assertThat(scmInfo.fileHash()).isEqualTo(hash);
+    assertThat(logTester.logs(TRACE)).containsOnly("Reading SCM info from DB for file 'FILE_UUID'");
+  }
+
+  @Test
   public void return_empty_if_no_dto_available() {
     analysisMetadataHolder.setBaseAnalysis(baseProjectAnalysis);
     analysisMetadataHolder.setBranch(null);
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/SpringProjectScanContainer.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/SpringProjectScanContainer.java
index aebe65007de..ca4a9cae98a 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/SpringProjectScanContainer.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/SpringProjectScanContainer.java
@@ -44,9 +44,9 @@ import org.sonar.scanner.bootstrap.ExtensionMatcher;
 import org.sonar.scanner.bootstrap.GlobalAnalysisMode;
 import org.sonar.scanner.bootstrap.PostJobExtensionDictionary;
 import org.sonar.scanner.cache.AnalysisCacheEnabled;
-import org.sonar.scanner.cache.DefaultAnalysisCacheLoader;
 import org.sonar.scanner.cache.AnalysisCacheMemoryStorage;
 import org.sonar.scanner.cache.AnalysisCacheProvider;
+import org.sonar.scanner.cache.DefaultAnalysisCacheLoader;
 import org.sonar.scanner.ci.CiConfigurationProvider;
 import org.sonar.scanner.ci.vendors.AppVeyor;
 import org.sonar.scanner.ci.vendors.AwsCodeBuild;
@@ -81,6 +81,7 @@ import org.sonar.scanner.postjob.PostJobOptimizer;
 import org.sonar.scanner.postjob.PostJobsExecutor;
 import org.sonar.scanner.qualitygate.QualityGateCheck;
 import org.sonar.scanner.report.ActiveRulesPublisher;
+import org.sonar.scanner.report.AnalysisCachePublisher;
 import org.sonar.scanner.report.AnalysisContextReportPublisher;
 import org.sonar.scanner.report.AnalysisWarningsPublisher;
 import org.sonar.scanner.report.CeTaskReportDataHolder;
@@ -88,7 +89,6 @@ import org.sonar.scanner.report.ChangedLinesPublisher;
 import org.sonar.scanner.report.ComponentsPublisher;
 import org.sonar.scanner.report.ContextPropertiesPublisher;
 import org.sonar.scanner.report.MetadataPublisher;
-import org.sonar.scanner.report.AnalysisCachePublisher;
 import org.sonar.scanner.report.ReportPublisher;
 import org.sonar.scanner.report.SourcePublisher;
 import org.sonar.scanner.report.TestExecutionPublisher;
@@ -241,12 +241,12 @@ public class SpringProjectScanContainer extends SpringComponentContainer {
       AnalysisContextReportPublisher.class,
       MetadataPublisher.class,
       ActiveRulesPublisher.class,
-      AnalysisWarningsPublisher.class,
       ComponentsPublisher.class,
       AnalysisCachePublisher.class,
       TestExecutionPublisher.class,
       SourcePublisher.class,
       ChangedLinesPublisher.class,
+      AnalysisWarningsPublisher.class,
 
       CeTaskReportDataHolder.class,