Null reference exception when working copy has detached head

[davidwengier]

not sure how long it ran but:

S:\VS>git pr --remote origin
Azure Repos
Found 5888 objects to send. (2349 ms)

Unhandled Exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at GitPullRequest.Services.GitPullRequestService.FindPullRequests(IDictionary`2 gitRepositories, Branch branch) in C:\Source\github.com\jcansdale\GitPullRequest\GitPullRequest.Services\GitPullRequestService.cs:line 46
   at GitPullRequest.Program.<>c__DisplayClass21_0.<ListBranches>b__1(Branch b) in C:\Source\github.com\jcansdale\GitPullRequest\GitPullRequest\Program.cs:line 118
   at System.Linq.Enumerable.SelectManyIterator[TSource,TCollection,TResult](IEnumerable`1 source, Func`2 collectionSelector, Func`3 resultSelector)+MoveNext()
   at System.Linq.Enumerable.WhereEnumerableIterator`1.ToArray()
   at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
   at System.Linq.OrderedEnumerable`1.ToList()
   at GitPullRequest.Program.ListBranches(GitPullRequestService service, Repository repo, String remoteName) in C:\Source\github.com\jcansdale\GitPullRequest\GitPullRequest\Program.cs:line 116
   at GitPullRequest.Program.OnExecute() in C:\Source\github.com\jcansdale\GitPullRequest\GitPullRequest\Program.cs:line 60
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at McMaster.Extensions.CommandLineUtils.Conventions.ExecuteMethodConvention.Invoke(MethodInfo method, Object instance, Object[] arguments) in C:\projects\commandlineutils\src\CommandLineUtils\Conventions\ExecuteMethodConvention.cs:line 86
   at McMaster.Extensions.CommandLineUtils.Conventions.ExecuteMethodConvention.OnExecute(ConventionContext context) in C:\projects\commandlineutils\src\CommandLineUtils\Conventions\ExecuteMethodConvention.cs:line 64
   at McMaster.Extensions.CommandLineUtils.Conventions.ExecuteMethodConvention.<>c__DisplayClass0_0.<<Apply>b__0>d.MoveNext() in C:\projects\commandlineutils\src\CommandLineUtils\Conventions\ExecuteMethodConvention.cs:line 25
--- End of stack trace from previous location where exception was thrown ---
   at McMaster.Extensions.CommandLineUtils.CommandLineApplication.<>c__DisplayClass131_0.<OnExecute>b__0() in C:\projects\commandlineutils\src\CommandLineUtils\CommandLineApplication.cs:line 600
   at McMaster.Extensions.CommandLineUtils.CommandLineApplication.Execute[TApp](CommandLineContext context) in C:\projects\commandlineutils\src\CommandLineUtils\CommandLineApplication.Execute.cs:line 31
   at McMaster.Extensions.CommandLineUtils.CommandLineApplication.Execute[TApp](IConsole console, String[] args) in C:\projects\commandlineutils\src\CommandLineUtils\CommandLineApplication.Execute.cs:line 105
   at GitPullRequest.Program.Main(String[] args) in C:\Source\github.com\jcansdale\GitPullRequest\GitPullRequest\Program.cs:line 17

[davidwengier]

This isn't because of a detached head, or if it is then its the combination of that and something else

[rainersigwald]

Same repo state, 1.0.14:

S:\VS>powershell measure-command {git pr --remote origin}

Unhandled Exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at GitPullRequest.Services.GitPullRequestService.FindPullRequests(RemoteRepositoryCache remoteRepositoryCache, IList`1 upstreamRepositories, Branch branch) in C:\Source\github.com\jcansdale\GitPullRequest\GitPullRequest.Services\GitPullRequestService.cs:line 41
   at GitPullRequest.Program.<>c__DisplayClass21_0.<ListBranches>b__1(Branch b) in C:\Source\github.com\jcansdale\GitPullRequest\GitPullRequest\Program.cs:line 124
   at System.Linq.Enumerable.SelectManyIterator[TSource,TCollection,TResult](IEnumerable`1 source, Func`2 collectionSelector, Func`3 resultSelector)+MoveNext()
   at System.Linq.Enumerable.WhereEnumerableIterator`1.ToArray()
   at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
   at System.Linq.OrderedEnumerable`1.ToList()
   at GitPullRequest.Program.ListBranches(GitPullRequestService service, Repository repo, String remoteName, Action`1 exceptionLogger) in C:\Source\github.com\jcansdale\GitPullRequest\GitPullRequest\Program.cs:line 122
   at GitPullRequest.Program.OnExecute() in C:\Source\github.com\jcansdale\GitPullRequest\GitPullRequest\Program.cs:line 63
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at McMaster.Extensions.CommandLineUtils.Conventions.ExecuteMethodConvention.Invoke(MethodInfo method, Object instance, Object[] arguments) in C:\projects\commandlineutils\src\CommandLineUtils\Conventions\ExecuteMethodConvention.cs:line 86
   at McMaster.Extensions.CommandLineUtils.Conventions.ExecuteMethodConvention.OnExecute(ConventionContext context) in C:\projects\commandlineutils\src\CommandLineUtils\Conventions\ExecuteMethodConvention.cs:line 64
   at McMaster.Extensions.CommandLineUtils.Conventions.ExecuteMethodConvention.<>c__DisplayClass0_0.<<Apply>b__0>d.MoveNext() in C:\projects\commandlineutils\src\CommandLineUtils\Conventions\ExecuteMethodConvention.cs:line 25
--- End of stack trace from previous location where exception was thrown ---
   at McMaster.Extensions.CommandLineUtils.CommandLineApplication.<>c__DisplayClass131_0.<OnExecute>b__0() in C:\projects\commandlineutils\src\CommandLineUtils\CommandLineApplication.cs:line 600
   at McMaster.Extensions.CommandLineUtils.CommandLineApplication.Execute[TApp](CommandLineContext context) in C:\projects\commandlineutils\src\CommandLineUtils\CommandLineApplication.Execute.cs:line 31
   at McMaster.Extensions.CommandLineUtils.CommandLineApplication.Execute[TApp](IConsole console, String[] args) in C:\projects\commandlineutils\src\CommandLineUtils\CommandLineApplication.Execute.cs:line 105
   at GitPullRequest.Program.Main(String[] args) in C:\Source\github.com\jcansdale\GitPullRequest\GitPullRequest\Program.cs:line 18


Days              : 0
Hours             : 0
Minutes           : 5
Seconds           : 17
Milliseconds      : 297
Ticks             : 3172970569
TotalDays         : 0.0036724196400463
TotalHours        : 0.0881380713611111
TotalMinutes      : 5.28828428166667
TotalSeconds      : 317.2970569
TotalMilliseconds : 317297.0569

[jcansdale]

Thanks for the trace. It does look like a branch doesn't have an Tip commit:
https://github.com/jcansdale/GitPullRequest/blob/master/GitPullRequest.Services/GitPullRequestService.cs#L41

I must have been looking at the wrong source when I checked the first time!

[jcansdale]

This is actually different to a detached head. A detached head would look like this:

The exception is showing a branch with no commits. Strange. 🤔