Add test for multiple branch config matches

This adds a test for validating that the first matched branch
configuration will be chosen when multiple are present that match the
current branch.

Author: cvpcs

src/GitVersionCore.Tests/GitVersionContextTests.cs

@@ -62,6 +62,38 @@ public void UsesBranchSpecificConfigOverTopLevelDefaults()
             context.Configuration.Tag.ShouldBe("alpha");
         }
 
+        [Test]
+        public void UsesFirstBranchConfigWhenMultipleMatch()
+        {
+            var config = new Config
+            {
+                VersioningMode = VersioningMode.ContinuousDelivery,
+                Branches =
+                {
+                    { "release/latest", new BranchConfig { Increment = IncrementStrategy.None, Regex = "release/latest" } },
+                    { "release", new BranchConfig { Increment = IncrementStrategy.Patch, Regex = "releases?[/-]" } }
+                }
+            }.ApplyDefaults();
+
+            var releaseLatestBranch = new MockBranch("release/latest") { new MockCommit { CommitterEx = Generate.SignatureNow() } };
+            var releaseVersionBranch = new MockBranch("release/1.0.0") { new MockCommit { CommitterEx = Generate.SignatureNow() } };
+
+            var mockRepository = new MockRepository
+            {
+                Branches = new MockBranchCollection
+                {
+                    releaseLatestBranch,
+                    releaseVersionBranch
+                }
+            };
+
+            var latestContext = new GitVersionContext(mockRepository, releaseLatestBranch, config);
+            latestContext.Configuration.Increment.ShouldBe(IncrementStrategy.None);
+
+            var versionContext = new GitVersionContext(mockRepository, releaseVersionBranch, config);
+            versionContext.Configuration.Increment.ShouldBe(IncrementStrategy.Patch);
+        }
+
         [Test]
         public void CanFindParentBranchForInheritingIncrementStrategy()
         {

src/GitVersionCore/BranchConfigurationCalculator.cs

@@ -30,6 +30,15 @@ public static KeyValuePair<string, BranchConfig> GetBranchConfiguration(Commit c
                 var keyValuePair = matchingBranches[0];
                 var branchConfiguration = keyValuePair.Value;
 
+                if (matchingBranches.Length > 1)
+                {
+                    Logger.WriteInfo(string.Format(
+                        "Multiple branch configurations match the current branch branchName of '{0}'. Using the first matching configuration, '{1}'. Matching configurations include: '{2}'",
+                        currentBranch.FriendlyName,
+                        keyValuePair.Key,
+                        string.Join("', '", matchingBranches.Select(b => b.Key))));
+                }
+
                 if (branchConfiguration.Increment == IncrementStrategy.Inherit)
                 {
                     return InheritBranchConfiguration(onlyEvaluateTrackedBranches, repository, currentCommit, currentBranch, keyValuePair, branchConfiguration, config, excludedInheritBranches);