+/*
+ * Lookup the tracking branch for the given branch and if present, optionally
+ * compute the commit ahead/behind values for the pair.
+ *
+ * If for_push is true, the tracking branch refers to the push branch,
+ * otherwise it refers to the upstream branch.
+ *
+ * The name of the tracking branch (or NULL if it is not defined) is
+ * returned via *tracking_name, if it is not itself NULL.
+ *
+ * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
+ * counts in *num_ours and *num_theirs. If abf is AHEAD_BEHIND_QUICK, skip
+ * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
+ * set to zero).
+ *
+ * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
+ * upstream defined, or ref does not exist). Returns 0 if the commits are
+ * identical. Returns 1 if commits are different.
+ */
+int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
+ const char **tracking_name, int for_push,
+ enum ahead_behind_flags abf)
+{
+ const char *base;
+
+ /* Cannot stat unless we are marked to build on top of somebody else. */
+ base = for_push ? branch_get_push(branch, NULL) :
+ branch_get_upstream(branch, NULL);
+ if (tracking_name)
+ *tracking_name = base;
+ if (!base)
+ return -1;
+
+ return stat_branch_pair(branch->refname, base, num_ours, num_theirs, abf);
+}
+