[Bug]: face-remap divergent?

[chxp]

Bug summary

Problem

Use the following config, Neomacs divergent from Emacs (I prefer white bg in org mode):

(defun my-org-white-bg ()
  (face-remap-add-relative  'default  '(:background "black" :foreground "white"))
  )
(add-hook 'org-mode-hook 'my-org-white-bg)

• In emacs, it is:

• In neomacs, it is:

The same problem?

In neomacs -Q -nw，then C-x 3, the two windows display the different faces:

[eval-exec]

confirmed. Investigating...

[eval-exec]

Fixed on main in 9af113d52 (fix(tui): keep split blank rows on default face).

Reproduced the issue with a new TUI regression before the fix: after C-x 3, blank body cells in the left split used the TTY vertical-border/mode-line-inactive background (Rgb(77,77,77)), while the matching blank cells in the right split used terminal Default.

Root cause: terminal right-border installation was padding blank rows with spaces using the vertical-border face. The fix keeps those padding spaces on the default face and applies the border face only to the actual border glyph.

Verification after the fix:

• cargo xtask fresh-build --release passed
• cargo nextest run -p neomacs-tui-tests --release scratch_comment_face_renders_same_buffer_consistently_after_cx3_split --no-capture passed
• cargo nextest run -p neomacs-tui-tests --release default_face_remap_renders_same_buffer_consistently_after_cx3_split --no-capture passed
• cargo nextest run -p neomacs-tui-tests --release boot_blank_cells_use_terminal_default_background --no-capture passed

I also checked GNU Emacs source for the relevant behavior: on TTY, vertical-border inherits mode-line-inactive, while terminal clear-to-EOL uses the terminal background/default highlight path, so blank padding should not inherit the border face.

[eval-exec]

Fixed the GUI/org screenshot case on main in ca24abd (fix(gui): honor buffer default face remap).

Reproduced with the org-mode hook from the issue: before this fix, face-remapping-alist remapped text glyph faces but the GUI window background rectangle still used the global default face, so blank org body space stayed white. After the fix, WindowParams.default_fg/default_bg and the buffer-source default face are resolved through the buffer-local remapped default face.

GNU source check: face-remap-add-relative makes face-remapping-alist buffer-local, and xdisp.c explicitly uses lookup_basic_face(... DEFAULT_FACE_ID) when extending blank space if the default face is remapped, so the blank body area should follow the remapped default face.

Verification:

• cargo nextest run -p neomacs-layout-engine default_face_plan_uses_buffer_default_face_remap window_params_default_colors_follow_buffer_default_face_remap test_face_resolver_buffer_local_default_remap_applies_to_plain_text
• cargo nextest run -p neomacs-tui-tests default_face_remap_renders_same_buffer_consistently_after_cx3_split scratch_comment_face_renders_same_buffer_consistently_after_cx3_split boot_blank_cells_use_terminal_default_background
• cargo build -p neomacs --bin neomacs
• GUI repro screenshot: sampled org body pixels at left/right/lower body are black after applying the remap; echo area remains white.

[eval-exec]

neomacs -Q -nw，then C-x 3, the two windows display the different faces:

I confirm this issue has been fixed on main, will release v0.0.11 today.

[chxp]

I found the following config also displays divergent in blank lines:

Config:

(custom-set-faces
 '(org-block      ((t (:background  "gray93" ))))
 )

In emacs, it is:

In neomacs, it is white in blank lines: