René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Lookup a non existent commit crashes the process.","articleBody":"I am doing some analysis of a codebase over time using nodegit, I am getting commits from an outside source that may no longer exist.\n\nDoing `Commit.lookup` says it should be safe, but if I do a lookup with an invalid commit (but a full sha), I get the following error:\n\n```\ngood repo\n[Error: Object not found - failed to find pack entry (b5e13cc50f98d9a045bebadffacf396b9ee49ad5)]\nnode(16924,0x7fff73d77300) malloc: *** error for object 0x100d02be0: pointer being freed was not allocated\n*** set a breakpoint in malloc_error_break to debug\n```\n\nHere is some example code that causes the failure:\n\n``` JavaScript\nvar nodegit = require(\"nodegit\")\nvar Repo = nodegit.Repository\nvar Commit = nodegit.Commit\n\nRepo.open(\"/path/to/myrepo\").then(function(repo) {\n  console.log(\"good repo\")\n  // missing, but valid full length, sha\n  return Commit.lookup(repo, \"b5e13cc50f98d9a045bebadffacf396b9ee49ad5\").then(function(commit) {\n    console.log(commit.message())\n  }, function(err) { console.log(err); throw err})\n}, function(err) { console.log(err); throw err })\n\n\n```\n","author":{"url":"https://github.com/addisonj","@type":"Person","name":"addisonj"},"datePublished":"2015-01-15T20:27:38.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/353/nodegit/issues/353"}