Dear Maintainer,

Whenver you "Save as...", you cannot use the keyboard to navigate the dialog window that opens.

Normally you can simply press "Enter" on the keyboard to save with the default filename.

You should also be able to press "Tab" to cycle through the various options or buttons.

Currently the cursor is stuck in the filename field and you can't "Tab" out of it.  You have to use the mouse to press any buttons.

Dear Maintainer,

I experienced the same issue of the "Enter" key behavior on "Save File" dialogs. Downgrading the chromium to version 144.0.7559.109-2 reverts the behavior. The "Tab" key has no function on "Save File" dialogs in version 144.0.7559.109-2, so maybe its behavior is long existed and not caused by recent upgrade.

Running bisect-builds.py on the "Enter" key behavior between 144.0.7559.109(good) and 145.0.7632.75(bad) found the following result:

You are probably looking for a change made after 1564730 (build version: 145.0.7618.0) (known good), but no later than 1564737 (build version: 145.0.7618.0) (first known bad).
CHANGELOG URL:
https://chromium.googlesource.com/chromium/src/+log/392842e9bc78b094dbd5afe09c6df0fee200e13f..3165dd86ac4005b1f618d3865312c35934bc4690

The changes between 1564730 and 1564737 have 7 commits, and among them I think the commit "[GTK] Don't preselect file dialog accept buttons" caused the behavior change of the "Enter" key on "Save File" dialog. This commit is to solve a potential vulnerability that a site could steal user files via file upload, but it clear all preselect accept buttons for "upload", "save as" and "folder selection".

If I understand correctly, a site can not preselect the path where a download file will be saved to; it can only prefill a filename for the download file. If a file with the same filename existed, chromium will automatically choose a different name. Even the user change it to the same filename, GTK will prompt a dialog requiring the user to confirm overwriting the existing file. Also providing downloading will not leak user files to a site, I think preselect accept button for "Save File" dialog has no vulnerability, or the vulnerability is marginal. So I think the behavior should be restored for "Save File" dialog.

The following patch against version 149.0.7827.155-1 should be able to restore the behavior for "Save File" dialog only, although I am still building the chromium package with this patch and can not test it currently.
--- a/ui/gtk/select_file_dialog_linux_gtk.cc
+++ b/ui/gtk/select_file_dialog_linux_gtk.cc
@@ -523,7 +523,7 @@
   GtkWidget* dialog = GtkFileChooserDialogNew(
       title_string.c_str(), nullptr, GTK_FILE_CHOOSER_ACTION_SAVE,
       GetCancelLabel(), GTK_RESPONSE_CANCEL, GetSaveLabel(),
-      kResponseTypeAccept);
+      GTK_RESPONSE_ACCEPT);
   SetGtkTransientForAura(dialog, parent, platform_);

   AddFilters(GTK_FILE_CHOOSER(dialog));

Dear Maintainer,

I confirm that building the chormium package with this patch restores the "Enter" key function on "Save File" dialogs.