Fixed UpdateAssemblyInfo error when git repository exists but git.exe cannot be found.

src/Tools/UpdateAssemblyInfo/Main.cs

@@ -203,8 +203,12 @@ namespace UpdateAssemblyInfo
 		{
 			if (revisionNumber == null) {
 				if (Directory.Exists(".git")) {
+					try {
 						ReadRevisionNumberFromGit();
 						ReadBranchNameFromGit();
+					} catch (Exception ex) {
+						Console.WriteLine(ex.ToString());
+					}
 				} else {
 					Console.WriteLine("There's no git working copy in " + Path.GetFullPath("."));
 				}
@@ -234,10 +238,12 @@ namespace UpdateAssemblyInfo
 					}
 					revNum++;
 				}
-				revisionNumber = revNum.ToString();
 				p.WaitForExit();
 				if (p.ExitCode != 0)
 					throw new Exception("git-rev-list exit code was " + p.ExitCode);
+				// Only set revisionNuber once we ensured the operation was successful,
+				// so that we retrieve the number from the REVISION file in case of errors
+				revisionNumber = revNum.ToString();
 			}
 		}
 		
@@ -277,11 +283,11 @@ namespace UpdateAssemblyInfo
 				Console.WriteLine();
 				Console.WriteLine("Build continues with revision number '0'...");
 				
-				revisionNumber = "0";
-				gitCommitHash = "0000000000000000000000000000000000000000";
+				revisionNumber = null;
 			}
 			if (revisionNumber == null || revisionNumber.Length == 0) {
 				revisionNumber = "0";
+				gitCommitHash = "0000000000000000000000000000000000000000";
 				//throw new ApplicationException("Error reading revision number");
 			}
 		}