Infinite recursion protection

src/GitVersion.Core/Configuration/BranchConfigurationCalculator.cs

@@ -3,12 +3,14 @@
 using GitVersion.Extensions;
 using GitVersion.Logging;
 using GitVersion.Model.Configuration;
+using GitVersion.Model.Exceptions;
 
 namespace GitVersion.Configuration;
 
 public class BranchConfigurationCalculator : IBranchConfigurationCalculator
 {
     private const string FallbackConfigName = "Fallback";
+    private const int MaxRecursions = 50;
 
     private readonly ILog log;
     private readonly IRepositoryStore repositoryStore;
@@ -22,8 +24,16 @@ public BranchConfigurationCalculator(ILog log, IRepositoryStore repositoryStore)
     /// <summary>
     /// Gets the <see cref="BranchConfig"/> for the current commit.
     /// </summary>
-    public BranchConfig GetBranchConfiguration(IBranch targetBranch, ICommit? currentCommit, Config configuration, IList<IBranch>? excludedInheritBranches = null)
+    public BranchConfig GetBranchConfiguration(IBranch targetBranch, ICommit? currentCommit, Config configuration, IList<IBranch>? excludedInheritBranches = null) =>
+        GetBranchConfigurationInternal(0, targetBranch, currentCommit, configuration, excludedInheritBranches);
+
+    private BranchConfig GetBranchConfigurationInternal(int recursions, IBranch targetBranch, ICommit? currentCommit, Config configuration, IList<IBranch>? excludedInheritBranches = null)
     {
+        if (recursions >= MaxRecursions)
+        {
+            throw new InfiniteLoopProtectionException($"Inherited branch configuration caused {recursions} recursions. Aborting!");
+        }
+
         var matchingBranches = configuration.GetConfigForBranch(targetBranch.Name.WithoutRemote);
 
         if (matchingBranches == null)
@@ -41,7 +51,7 @@ public BranchConfig GetBranchConfiguration(IBranch targetBranch, ICommit? curren
 
         if (matchingBranches.Increment == IncrementStrategy.Inherit)
         {
-            matchingBranches = InheritBranchConfiguration(targetBranch, matchingBranches, currentCommit, configuration, excludedInheritBranches);
+            matchingBranches = InheritBranchConfiguration(recursions, targetBranch, matchingBranches, currentCommit, configuration, excludedInheritBranches);
             if (matchingBranches.Name!.IsEquivalentTo(FallbackConfigName) && matchingBranches.Increment == IncrementStrategy.Inherit)
             {
                 // We tried, and failed to inherit, just fall back to patch
@@ -50,13 +60,16 @@ public BranchConfig GetBranchConfiguration(IBranch targetBranch, ICommit? curren
         }
 
         return matchingBranches;
+
     }
 
     // TODO I think we need to take a fresh approach to this.. it's getting really complex with heaps of edge cases
-    private BranchConfig InheritBranchConfiguration(IBranch targetBranch, BranchConfig branchConfiguration, ICommit? currentCommit, Config configuration, IList<IBranch>? excludedInheritBranches)
+    private BranchConfig InheritBranchConfiguration(int recursions, IBranch targetBranch, BranchConfig branchConfiguration, ICommit? currentCommit, Config configuration, IList<IBranch>? excludedInheritBranches)
     {
         using (this.log.IndentLog("Attempting to inherit branch configuration from parent branch"))
         {
+            recursions += 1;
+
             var excludedBranches = new[] { targetBranch };
             // Check if we are a merge commit. If so likely we are a pull request
             var parentCount = currentCommit?.Parents.Count();
@@ -106,7 +119,7 @@ private BranchConfig InheritBranchConfiguration(IBranch targetBranch, BranchConf
 
             if (possibleParents.Count == 1)
             {
-                var branchConfig = GetBranchConfiguration(possibleParents[0], currentCommit, configuration, excludedInheritBranches);
+                var branchConfig = GetBranchConfigurationInternal(recursions, possibleParents[0], currentCommit, configuration, excludedInheritBranches);
                 // If we have resolved a fallback config we should not return that we have got config
                 if (branchConfig.Name != FallbackConfigName)
                 {
@@ -154,13 +167,14 @@ private BranchConfig InheritBranchConfiguration(IBranch targetBranch, BranchConf
                 };
             }
 
-            var inheritingBranchConfig = GetBranchConfiguration(chosenBranch, currentCommit, configuration, excludedInheritBranches)!;
+            var inheritingBranchConfig = GetBranchConfigurationInternal(recursions, chosenBranch, currentCommit, configuration, excludedInheritBranches)!;
             var configIncrement = inheritingBranchConfig.Increment;
             if (inheritingBranchConfig.Name!.IsEquivalentTo(FallbackConfigName) && configIncrement == IncrementStrategy.Inherit)
             {
                 this.log.Warning("Fallback config inherits by default, dropping to patch increment");
                 configIncrement = IncrementStrategy.Patch;
             }
+
             return new BranchConfig(branchConfiguration)
             {
                 Increment = configIncrement,
@@ -212,8 +226,8 @@ private IBranch[] CalculateWhenMultipleParents(ICommit currentCommit, ref IBranc
     private static BranchConfig? ChooseMainOrDevelopIncrementStrategyIfTheChosenBranchIsOneOfThem(IBranch chosenBranch, BranchConfig branchConfiguration, Config config)
     {
         BranchConfig? mainOrDevelopConfig = null;
-        var developBranchRegex = config.Branches[Config.DevelopBranchKey]?.Regex;
-        var mainBranchRegex = config.Branches[Config.MainBranchKey]?.Regex;
+        var developBranchRegex = config.Branches[Config.DevelopBranchKey]?.Regex ?? Config.DevelopBranchRegex;
+        var mainBranchRegex = config.Branches[Config.MainBranchKey]?.Regex ?? Config.MainBranchRegex;
         if (Regex.IsMatch(chosenBranch.Name.Friendly, developBranchRegex, RegexOptions.IgnoreCase))
         {
             // Normally we would not expect this to happen but for safety we add a check

src/GitVersion.Core/Model/Exceptions/InfiniteLoopProtectionException.cs

@@ -0,0 +1,10 @@
+namespace GitVersion.Model.Exceptions
+{
+    public class InfiniteLoopProtectionException : Exception
+    {
+        public InfiniteLoopProtectionException(string messageFormat)
+            : base(messageFormat)
+        {
+        }
+    }
+}