From bc7db4ba8a766085e1c71224f9d2ee69aa45d395 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlos=20Mart=C3=ADn=20Nieto?= <carlos@cmartin.tk>
Date: Fri, 3 Feb 2012 18:31:19 +0100
Subject: [PATCH] errors: don't segfault if the library didn't set an error

git_lasterror() can return NULL. Passing that to the error formatting
functions leads to a segmentation fault.

Add a wrapper with a generic "no more information" string for the
cases when the library didn't set one.
---
 pygit2.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/pygit2.c b/pygit2.c
index a1fab76..0b74ff5 100644
--- a/pygit2.c
+++ b/pygit2.c
@@ -174,6 +174,20 @@ Error_type(int err)
     }
 }
 
+/*
+ * Python doesn't like it when the error string is NULL. Not giving
+ * back an error string could be a bug in the library
+ */
+static const char *
+git_last_error(void)
+{
+	const char *ret;
+
+	ret = git_lasterror();
+
+	return ret != NULL ? ret : "(No error information given)";
+}
+
 static PyObject *
 Error_set(int err)
 {
@@ -182,7 +196,7 @@ Error_set(int err)
     if (err == GIT_EOSERR)
         return PyErr_SetFromErrno(GitError);
 
-    PyErr_SetString(Error_type(err), git_lasterror());
+    PyErr_SetString(Error_type(err), git_last_error());
     return NULL;
 }
 
@@ -195,7 +209,7 @@ Error_set_str(int err, const char *str)
         return NULL;
     }
 
-    return PyErr_Format(Error_type(err), "%s: %s", str, git_lasterror());
+    return PyErr_Format(Error_type(err), "%s: %s", str, git_last_error());
 }
 
 static PyObject *