added fallback to GIT_BRANCH in case GIT_LOCAL_BRANCH is not defined

Author: Behrhorst

src/GitVersionCore.Tests/BuildServers/EnvironmentVariableJenkinsTests.cs

@@ -43,12 +43,17 @@ public void JenkinsTakesLocalBranchNameNotRemoteName()
         string branchOrig = Environment.GetEnvironmentVariable(branch);
         string localBranchOrig = Environment.GetEnvironmentVariable(localBranch);
 
-        // Set new Environment variables for testing
+        // Set GIT_BRANCH for testing
         Environment.SetEnvironmentVariable(branch, "origin/master");
-        Environment.SetEnvironmentVariable(localBranch, "master");
 
-        // Test Jenkins GetCurrentBranch method
+        // Test Jenkins that GetCurrentBranch falls back to GIT_BRANCH if GIT_LOCAL_BRANCH undefined
         var j = new Jenkins();
+        j.GetCurrentBranch(true).ShouldBe("origin/master");
+
+        // Set GIT_LOCAL_BRANCH
+        Environment.SetEnvironmentVariable(localBranch, "master");
+
+        // Test Jenkins GetCurrentBranch method now returns GIT_LOCAL_BRANCH
         j.GetCurrentBranch(true).ShouldBe("master");
 
         // Restore environment variables

src/GitVersionCore/BuildServers/Jenkins.cs

@@ -36,7 +36,7 @@ public override string[] GenerateSetParameterMessage(string name, string value)
 
         public override string GetCurrentBranch(bool usingDynamicRepos)
         {
-            return Environment.GetEnvironmentVariable("GIT_LOCAL_BRANCH");
+            return Environment.GetEnvironmentVariable("GIT_LOCAL_BRANCH") ?? Environment.GetEnvironmentVariable("GIT_BRANCH");
         }
 
         public override bool PreventFetch()