From d04bb12a0998b910b51065ed1364989bc3d9ae45 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 16 Aug 2025 17:33:00 +0530
Subject: [PATCH] Use absolute path when serializing foreground process

---
 kitty/child.py             |  7 +++++++
 kitty/fast_data_types.pyi  |  2 ++
 kitty/macos_process_info.c | 14 ++++++++++++++
 kitty/window.py            |  4 ++++
 4 files changed, 27 insertions(+)

diff --git a/kitty/child.py b/kitty/child.py
index 69ada6cf0..2f5a8f6ac 100644
--- a/kitty/child.py
+++ b/kitty/child.py
@@ -20,6 +20,7 @@
 
 
 if is_macos:
+    from kitty.fast_data_types import abspath_of_process as _abspath_of_process
     from kitty.fast_data_types import cmdline_of_process as cmdline_
     from kitty.fast_data_types import cwd_of_process as _cwd
     from kitty.fast_data_types import environ_of_process as _environ_of_process
@@ -30,6 +31,9 @@ def cwd_of_process(pid: int) -> str:
         # anyway but we use realpath for extra safety.
         return os.path.realpath(_cwd(pid))
 
+    def abspath_of_exe(pid: int) -> str:
+        return os.path.realpath(_abspath_of_process(pid))
+
     def process_group_map() -> DefaultDict[int, list[int]]:
         ans: DefaultDict[int, list[int]] = defaultdict(list)
         for pid, pgid in _process_group_map():
@@ -82,6 +86,9 @@ def process_group_map() -> DefaultDict[int, list[int]]:
             ans[q].append(pid)
         return ans
 
+    def abspath_of_exe(pid: int) -> str:
+        return os.path.realpath(f'/proc/{pid}/exe')
+
 
 @run_once
 def checked_terminfo_dir() -> str | None:
diff --git a/kitty/fast_data_types.pyi b/kitty/fast_data_types.pyi
index bbd8da152..e7a0e98d8 100644
--- a/kitty/fast_data_types.pyi
+++ b/kitty/fast_data_types.pyi
@@ -383,6 +383,8 @@ def cwd_of_process(pid: int) -> str:
     pass
 
 
+def abspath_of_process(pid: int) -> str: ...
+
 def default_color_table() -> Tuple[int, ...]:
     pass
 
diff --git a/kitty/macos_process_info.c b/kitty/macos_process_info.c
index aa65a2e61..a81f6f2a4 100644
--- a/kitty/macos_process_info.c
+++ b/kitty/macos_process_info.c
@@ -22,6 +22,19 @@ cwd_of_process(PyObject *self UNUSED, PyObject *pid_) {
     return PyUnicode_FromString(vpi.pvi_cdir.vip_path);
 }
 
+static PyObject*
+abspath_of_process(PyObject *self UNUSED, PyObject *pid_) {
+    if (!PyLong_Check(pid_)) { PyErr_SetString(PyExc_TypeError, "pid must be an int"); return NULL; }
+    long pid = PyLong_AsLong(pid_);
+    if (pid < 0) { PyErr_SetString(PyExc_TypeError, "pid cannot be negative"); return NULL; }
+    char pathbuf[PROC_PIDPATHINFO_MAXSIZE+1];
+    int ret = proc_pidpath(pid, pathbuf, sizeof(pathbuf));
+    if (ret <= 0) {
+        PyErr_SetFromErrno(PyExc_OSError); return NULL;
+    }
+    return PyUnicode_FromString(pathbuf);
+}
+
 // Read the maximum argument size for processes
 static int
 get_argmax(void) {
@@ -272,6 +285,7 @@ error:
 
 static PyMethodDef module_methods[] = {
     {"cwd_of_process", (PyCFunction)cwd_of_process, METH_O, ""},
+    {"abspath_of_process", (PyCFunction)abspath_of_process, METH_O, ""},
     {"cmdline_of_process", (PyCFunction)cmdline_of_process, METH_O, ""},
     {"environ_of_process", (PyCFunction)environ_of_process, METH_O, ""},
     {"get_all_processes", (PyCFunction)get_all_processes, METH_NOARGS, ""},
diff --git a/kitty/window.py b/kitty/window.py
index 2d74c7e7f..e28d036df 100644
--- a/kitty/window.py
+++ b/kitty/window.py
@@ -2012,6 +2012,10 @@ def as_launch_command(self, ser_opts: SaveAsSessionOptions, is_overlay: bool = F
                 fcmd = self.child.cmdline_of_pid(pid)
                 if fcmd:
                     unserialize_data['cmd_at_shell_startup'] = fcmd
+                    if not os.path.isabs(fcmd[0]):
+                        with suppress(Exception):
+                            from .child import abspath_of_exe
+                            fcmd[0] = abspath_of_exe(pid)
         ans.insert(1, unserialize_launch_flag + json.dumps(unserialize_data))
         ans.extend(cmd)
         return ans