[Rollout] Production Rollout 2025 05 09 (#4824)

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#4823

Author: dkurepa

src/Maestro/Maestro.MergePolicies/BackFlowMergePolicy.cs

@@ -77,7 +77,7 @@ private static List<string> CalculateConfigurationErrors(
         PullRequestUpdateSummary pr,
         SubscriptionUpdateSummary update)
     {
-        List<string> configurationErrors = new();
+        List<string> configurationErrors = [];
         if (sourceDependency.BarId != update.BuildId)
         {
             configurationErrors.Add($"""
@@ -96,16 +96,6 @@ private static List<string> CalculateConfigurationErrors(
                 """);
         }
 
-        (string targetRepoName, _) = GitRepoUrlUtils.GetRepoNameAndOwner(pr.TargetRepoUrl);
-        if (!targetRepoName.Equals(sourceDependency.Mapping, StringComparison.OrdinalIgnoreCase))
-        {
-            configurationErrors.Add($"""
-                #### {configurationErrors.Count + 1}. Mapping Mismatch in `{VersionFiles.VersionDetailsXml}`
-                - **Source Repository**: {update.SourceRepo}
-                - **Error**: Mapping value `{sourceDependency.Mapping}` found in `{VersionFiles.VersionDetailsXml}` does not match the source repository name of the current update (`{targetRepoName}`).
-                """);
-        }
-
         if (sourceDependency.Uri != update.SourceRepo)
         {
             configurationErrors.Add($"""

src/Microsoft.DotNet.Darc/DarcLib/VirtualMonoRepo/VmrForwardFlower.cs

@@ -427,7 +427,7 @@ await repo.CommitAsync(
             {
                 await repo.CommitAsync(
                     $"Merge branch {branchToMerge} into {targetBranch}",
-                    allowEmpty: false,
+                    allowEmpty: true,
                     cancellationToken: CancellationToken.None);
             }
             catch (Exception e) when (e.Message.Contains("Your branch is ahead of"))
@@ -512,12 +512,18 @@ private async Task TryResolvingSourceManifestConflict(ILocalGitRepo vmr, string
             updatedMapping.PackageVersion,
             updatedMapping.BarId);
 
-        foreach (var submodule in theirSourceManifest.Submodules.Where(s => s.Path.StartsWith(mappingName + "/")))
+        var theirAffectedSubmodules = theirSourceManifest.Submodules
+            .Where(s => s.Path.StartsWith(mappingName + "/"))
+            .ToList();
+        foreach (var submodule in theirAffectedSubmodules)
         {
             theirSourceManifest.RemoveSubmodule(submodule);
         }
 
-        foreach (var submodule in _sourceManifest.Submodules.Where(s => s.Path.StartsWith(mappingName + "/")))
+        var ourAffectedSubmodules = ourSourceManifest.Submodules
+            .Where(s => s.Path.StartsWith(mappingName + "/"))
+            .ToList();
+        foreach (var submodule in ourAffectedSubmodules)
         {
             theirSourceManifest.UpdateSubmodule(submodule);
         }