Merge branch 'sb/hook-cleanup'

* sb/hook-cleanup:
  run_hook(): allow more than 9 hook arguments
  run_hook(): check the executability of the hook before filling argv
  api-run-command.txt: talk about run_hook()
  Move run_hook() from builtin-commit.c into run-command.c (libgit)
  checkout: don't crash on file checkout before running post-checkout hook

Documentation/technical/api-run-command.txt

@@ -52,6 +52,21 @@ Functions
 	Wait for the completion of an asynchronous function that was
 	started with start_async().
 
+`run_hook`::
+
+	Run a hook.
+	The first argument is a pathname to an index file, or NULL
+	if the hook uses the default index file or no index is needed.
+	The second argument is the name of the hook.
+	The further arguments correspond to the hook arguments.
+	The last argument has to be NULL to terminate the arguments list.
+	If the hook does not exist or is not executable, the return
+	value will be zero.
+	If it is executable, the hook will be executed and the exit
+	status of the hook is returned.
+	On execution, .stdout_to_stderr and .no_stdin will be set.
+	(See below.)
+
 
 Data structures
 ---------------