feat(autochdir): extract CWD from term:// URI

[zeertzjq]

Inspired by #2252 and #16740.

[glacambre]

Thanks a lot for making this change, and sorry it took me a long time to review. I rebased #16740 on top of your PR, and then applied the following change:

diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 7701688b4..6961c3c29 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -11476,7 +11476,7 @@ static void f_termopen(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   // the 'swapfile' option to ensure no swap file will be created
   curbuf->b_p_swf = false;
   (void)setfname(curbuf, NameBuff, NULL, true);
-  // Save the job id and pid in b:terminal_job_{id,pid}
+  // Save the job id, pid and command in b:terminal_job_{id,pid,cmd}
   Error err = ERROR_INIT;
   // deprecated: use 'channel' buffer option
   dict_set_var(curbuf->b_vars, cstr_as_string("terminal_job_id"),
@@ -11485,6 +11485,9 @@ static void f_termopen(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   dict_set_var(curbuf->b_vars, cstr_as_string("terminal_job_pid"),
                INTEGER_OBJ(pid), false, false, &err);
   api_clear_error(&err);
+  dict_set_var(curbuf->b_vars, cstr_as_string("terminal_job_cmd"),
+               STRING_OBJ(cstr_to_string(cmd)), false, false, &err);
+  api_clear_error(&err);
 
   channel_terminal_open(curbuf, chan);
   channel_create_event(chan, NULL);
diff --git a/src/nvim/terminal.c b/src/nvim/terminal.c
index d1113e031..5ff74e393 100644
--- a/src/nvim/terminal.c
+++ b/src/nvim/terminal.c
@@ -186,16 +186,24 @@ int handle_osc_7(const char *command, size_t cmdlen, void *user)
     first_separator += 1;
   }
 
-  // Copy new directory to buffer local dir
   buf_T *buf = handle_get_buffer(term->buf_handle);
-  xfree(buf->b_ffname);
-  command_end[0] = '/';
-  command_end[1] = '\0';
-  buf->b_ffname = (char_u *)xstrdup(first_separator);
+
+  varnumber_T pid = tv_dict_get_number(buf->b_vars, "terminal_job_pid");
+  char* cmd = tv_dict_get_string(buf->b_vars, "terminal_job_cmd", true);
+
+  command_end[0] = '\0';
+  snprintf((char *)NameBuff, sizeof(NameBuff), "term://%s//%li:%s",
+      (char *)first_separator, pid, cmd);
   command_end[0] = '\033';
-  command_end[1] = '\\';
 
-  do_autochdir();
+  xfree(cmd);
+  xfree(buf->b_ffname);
+  buf->b_ffname = vim_strsave(NameBuff);
+
+  do_autochdir();
 
   return 1;
 }

And it works!

That, combined with the fact that I'm not seeing anything wrong in your code, leads me to think that this is ready to be merged :)

[zeertzjq]

I recently noticed that Vim has an 'autoshelldir' option, so I'm now a bit hesitant about this. The term:// URI may also be subject to future changes.

[glacambre]

@zeertzjq I think I agree. I'll try to port vim patch v8.2.2675 and close my PR if I succeed.