tabs: an unnamed tab borrows the directory its focused pane is in

name, then purpose, then the basename of the focused pane's cwd, then
the bare number. The kernel's answer (live_cwd, the same question
save-workspace already asks), so a cd moves the label with you; home
shows as ~. The focused pane rather than any consensus of the tab's
panes: when they sit in different directories, the one you are typing
into is what the tab is about, and a rule anyone can predict beats a
cleverer one nobody can. Derived at draw time and never stored, so a
real name wins the moment one exists, dumps and the tabs JSON stay
unpolluted, and renaming starts from a genuinely empty name.

2 files changed, 55 insertions, 0 deletions

diff --git a/src/app_draw.c b/src/app_draw.c
index 5d358ad..b61d330 100644
--- a/src/app_draw.c
+++ b/src/app_draw.c
@@ -4,6 +4,7 @@
 
 #include <ghostty/vt.h>
 #include <ctype.h>
+#include <limits.h>
 #include <stdarg.h>
 #include <time.h>
 #include <sys/stat.h>
@@ -1793,6 +1794,29 @@ static uint16_t draw_tab_cell(app_t *a, screen_t *s, size_t i, uint16_t x,
   tab_t *t = &a->tabs[i];
   char label[96];
   const char *nm = t->name[0] ? t->name : (t->purpose[0] ? t->purpose : "");
+  /* An unnamed tab borrows the name of the directory its focused pane is in
+   * -- the kernel's answer, so a `cd` moves the label with you. The focused
+   * pane rather than any consensus of the tab's panes: when they disagree,
+   * the one you are typing into is what the tab is about, and a rule anyone
+   * can predict beats a cleverer one nobody can. Derived at draw time and
+   * never stored, so a real name or a purpose wins the moment one exists. */
+  char derived[80];
+  if (!nm[0]) {
+    node_t *f = t->focus ? t->focus : first_leaf_of(t->root);
+    char buf[PATH_MAX];
+    const char *cwd = f && f->pane ? live_cwd(f->pane, buf, sizeof buf) : NULL;
+    if (cwd && cwd[0]) {
+      const char *home = getenv("HOME");
+      if (home && home[0] && strcmp(cwd, home) == 0) {
+        nm = "~";
+      } else {
+        const char *base = strrchr(cwd, '/');
+        snprintf(derived, sizeof derived, "%s",
+                 base && base[1] ? base + 1 : cwd);
+        nm = derived;
+      }
+    }
+  }
   /* A pane that rang in a tab you are not looking at is invisible without
    * this, and that is the case the whole indicator exists for. */
   bool rang = CFG.bell_indicator && tab_has_bell(t);
diff --git a/tests/test_tab_bar.py b/tests/test_tab_bar.py
index 9342905..47feba6 100644
--- a/tests/test_tab_bar.py
+++ b/tests/test_tab_bar.py
@@ -204,6 +204,34 @@ def test_a_dead_pane_reports_its_exit_instead():
         check("how it died replaces what it last said", "status 3" in row, repr(row))
 
 
+def test_an_unnamed_tab_borrows_its_directory():
+    cd = ["/bin/sh", "-c", "cd /tmp && stty raw -echo; cat"]
+    with Session(cd, cols=90, rows=20, config=LEFT) as s:
+        s.settle(60)
+        row = s.snapshot().line(2)[:W]
+        check("the label is the focused pane's dir", "1:tmp" in row, repr(row))
+
+
+def test_a_real_name_beats_the_derived_one():
+    lay = tempfile.NamedTemporaryFile("w", suffix=".layout", delete=False)
+    lay.write('layout {\n tab name="api" {\n  pane\n }\n}\n')
+    lay.close()
+    with Session(SH, cols=90, rows=20, config=LEFT, layout=lay.name) as s:
+        s.settle(60)
+        row = s.snapshot().line(2)[:W]
+        check("a declared name is not second-guessed", "1:api" in row, repr(row))
+
+
+def test_the_borrowed_name_follows_a_cd():
+    loop = ["/bin/sh", "-c", 'cd /tmp && while IFS= read -r l; do eval "$l"; done']
+    with Session(loop, cols=90, rows=20, config=LEFT) as s:
+        s.until(lambda snap: "1:tmp" in snap.line(2))
+        s.send(r"cd /home\n")
+        s.until(lambda snap: "1:home" in snap.line(2))
+        row = s.snapshot().line(2)[:W]
+        check("the kernel's answer moves the label", "1:home" in row, repr(row))
+
+
 def test_narrow_terminal_falls_back_to_top():
     # 40 < width + min_pane cols + 4: the sidebar would leave no room for the
     # pane it is chrome for, so the strip goes back to the top row.
@@ -242,6 +270,9 @@ if __name__ == "__main__":
     test_status_cap_spends_its_last_row_on_the_ellipsis()
     test_a_long_status_is_cut_and_says_so()
     test_a_dead_pane_reports_its_exit_instead()
+    test_an_unnamed_tab_borrows_its_directory()
+    test_a_real_name_beats_the_derived_one()
+    test_the_borrowed_name_follows_a_cd()
     test_narrow_terminal_falls_back_to_top()
     test_growing_back_restores_the_sidebar()
     sys.exit(report())