Merge branch 'rs/wt-status-detached-branch-fix' into maint

"git status --branch --short" accessed beyond the constant string
"HEAD", which has been corrected.

* rs/wt-status-detached-branch-fix:
wt-status: use skip_prefix() to get rid of magic string length constants
wt-status: don't skip a magical number of characters blindly
wt-status: avoid building bogus branch name with detached HEAD
wt-status: exit early using goto in wt_shortstatus_print_tracking()
t7060: add test for status --branch on a detached HEAD

diff --cc t/t7060-wtstatus.sh
Simple merge

diff --cc wt-status.c
index 3e3b8c098924d655bccb395e95cee832abb1d39f,62383a27f93cf4594b0669a22fa14031931badcb..435fc2806ec0a59acf390ee89ed2efc79f229a0e
--- 1/wt-status.c
--- 2/wt-status.c
+++ b/wt-status.c
@@@ -1442,15 -1318,10 +1438,13 @@@ void wt_status_print(struct wt_status *
        if (s->branch) {
                const char *on_what = _("On branch ");
                const char *branch_name = s->branch;
-               if (starts_with(branch_name, "refs/heads/"))
-                       branch_name += 11;
-               else if (!strcmp(branch_name, "HEAD")) {
+               if (!strcmp(branch_name, "HEAD")) {
                        branch_status_color = color(WT_STATUS_NOBRANCH, s);
                        if (state.rebase_in_progress || state.rebase_interactive_in_progress) {
 -                              on_what = _("rebase in progress; onto ");
 +                              if (state.rebase_interactive_in_progress)
 +                                      on_what = _("interactive rebase in progress; onto ");
 +                              else
 +                                      on_what = _("rebase in progress; onto ");
                                branch_name = state.onto;
                        } else if (state.detached_from) {
                                branch_name = state.detached_from;