fix: put back only the font a firmware restores

ports/RetroBIOS/RetroBIOS.sh

@@ -60,6 +60,8 @@ if [ -e "${RB_ARK_MARKER:-/usr/share/plymouth/themes/text.plymouth}" ]; then
   RB_BIOS_DEST=$(awk -F'"' '/^system_directory *=/ { print $2; exit }' \
     "${RB_RETROARCH_CFG:-/home/ark/.config/retroarch/retroarch.cfg}" 2>/dev/null)
   RB_BIOS_DEST="${RB_BIOS_DEST:-/$directory/bios}"
+  # The font ArkOS's own tools put back on leaving (dArkOS_Tools/Wifi.sh).
+  RB_FONT_DEFAULT="Lat7-Terminus20x10"
 fi
 # shellcheck source=../shared/tui.txt
 source "$GAMEDIR/tui.txt"

ports/shared/tui.txt

@@ -30,6 +30,9 @@
 #   RB_BIOS_DEST   the one of them the firmware reads, never offered as the
 #                  other card
 #   RB_FALLBACK    1 when the launcher has screens of its own to fall back to
+#   RB_FONT_DEFAULT  the console font the firmware itself puts back, by
+#                  name (ArkOS: Lat7-Terminus20x10), for a setfont that
+#                  cannot save the one in place. Unset, the font is kept.
 #   RB_PAD         the input route, exported to the interface as
 #                  RETROBIOS_PAD: gptokeyb (retrobios.gptk, the default when
 #                  RB_MAPPER is set), muxterm (muxterm's own keys), evmapy
@@ -493,8 +496,9 @@ rb_route_ready() {
 # The largest Terminus font that keeps 56 columns and 20 rows, the way
 # dArkOS's own tools pick one per screen (Lat7-Terminus16 on 480x320,
 # TerminusBold22x11 on 640x480, 32x16 on 1024x768). Only changed when the
-# font in place can be put back: saved with setfont -O, or the
-# Lat7-Terminus20x10 ArkOS tools restore.
+# font in place can be put back: saved with setfont -O, or RB_FONT_DEFAULT,
+# the one the firmware's own tools restore. A fixed fallback gave a device
+# whose default differs another font after the run.
 rb_font_set() {
   command -v setfont >/dev/null 2>&1 || return 0
   local size width height spec fh fw name file="" fallback
@@ -524,7 +528,8 @@ rb_font_set() {
     RB_FONT_BACK="$RB_STATE/font.psf"
     return 0
   fi
-  fallback="$RB_FONTS/Lat7-Terminus20x10.psf.gz"
+  [ -n "${RB_FONT_DEFAULT:-}" ] || return 0
+  fallback="$RB_FONTS/$RB_FONT_DEFAULT.psf.gz"
   if [ -f "$fallback" ] && $ESUDO setfont -C "$RB_TTY" "$file" >> "$RB_LOG" 2>&1; then
     RB_FONT_BACK="$fallback"
   fi

ports/tools/RetroBIOS.sh

@@ -40,6 +40,8 @@ if [ -d "$ROOT/opt/system" ] && [ -d "$ROOT/opt/inttools" ]; then
   fi
   RB_ROUTES="vt"
   RB_CONSOLE="${RB_CONSOLE:-/dev/tty1}"
+  # The font ArkOS's own tools put back on leaving (dArkOS_Tools/Wifi.sh).
+  RB_FONT_DEFAULT="Lat7-Terminus20x10"
   RB_PACK_PATH="$RB_DIR:$HERE:/roms:/roms2"
   # The second card is /roms2, and "Switch to SD2 for Roms" moves RetroArch's
   # system folder there (dArkOS scripts/Switch to SD2 for Roms.sh:91-92): the

tests/test_handheld_launchers.py

@@ -1334,13 +1334,15 @@ class ThePortMasterPort(unittest.TestCase):
         device.assert_console_restored()
 
     def test_the_font_is_put_back_without_setfont_o(self):
-        """busybox setfont has no -O: the font is changed only when the
-        Lat7-Terminus20x10 ArkOS tools restore exists, and that one is put
+        """busybox setfont has no -O: on ArkOS the font is changed only when
+        the Lat7-Terminus20x10 its tools restore exists, and that one is put
         back."""
         device = self.device(FAKE_NO_SAVE="1")
         fonts = device.env["RB_FONTS"]
         (Path(fonts) / "Lat7-Terminus20x10.psf.gz").write_bytes(b"")
-        device.run(["bash", self.script])
+        marker = device.root / "text.plymouth"
+        marker.write_text("")
+        device.run(["bash", self.script], RB_ARK_MARKER=str(marker))
         chosen = f"{fonts}/Lat7-TerminusBold22x11.psf.gz"
         saved = str(self.gamedir / "run" / "font.psf")
         self.assertEqual(device.tools(), [
@@ -1349,6 +1351,14 @@ class ThePortMasterPort(unittest.TestCase):
             f"setfont -C {device.console} {fonts}/Lat7-Terminus20x10.psf.gz",
         ])
 
+    def test_elsewhere_a_font_that_cannot_be_saved_is_left(self):
+        """Lat7-Terminus20x10 is ArkOS's font: put back on another device,
+        it left the console in a font it never had."""
+        device = self.device(FAKE_NO_SAVE="1")
+        (Path(device.env["RB_FONTS"]) / "Lat7-Terminus20x10.psf.gz").write_bytes(b"")
+        device.run(["bash", self.script])
+        self.assertEqual(len([t for t in device.tools() if t.startswith("setfont")]), 1)
+
     def test_without_the_fallback_font_the_font_is_left(self):
         device = self.device(FAKE_NO_SAVE="1")
         device.run(["bash", self.script])