TextSnatcher on Wayland

[silvain]

TextSnatcher does not work with the “Take Screenshot” option on Wayland (Error reading image).
One workaround is to take a screenshot the usual way first (PrintSreen Key in my case), then use “Get from Clipboard” option in TextSnatcher.
This is bit frustrating and it produces an additional useless file in the screen captures folder.
Is there any way to have TextSnatcher fully functional on Wayland?

[Arthur031221]

TextSnatcher already uses the screenshot portal on Wayland, so there is no X11 setting you need to switch on. I found a concrete failure in its current screenshot path: save_shot() passes the portal's filename to read_image(), which builds a Tesseract command by concatenating that filename without quoting it. If the portal returns a screenshot path containing spaces, Tesseract receives the wrong arguments. The clipboard route uses a fixed /tmp/textshot.png path, which explains why it can work while Take Screenshot fails.

I checked how GLib parses the command line that TextSnatcher builds:

python3 - <<'PY'
import ctypes
G=ctypes.CDLL('libglib-2.0.so.0')
G.g_shell_parse_argv.argtypes=[ctypes.c_char_p,ctypes.POINTER(ctypes.c_int),ctypes.POINTER(ctypes.POINTER(ctypes.c_char_p)),ctypes.POINTER(ctypes.c_void_p)]
for label,path in [('unquoted','/tmp/Screenshot from Portal.png'),('quoted',"'/tmp/Screenshot from Portal.png'")]:
 n=ctypes.c_int();v=ctypes.POINTER(ctypes.c_char_p)();e=ctypes.c_void_p()
 assert G.g_shell_parse_argv(f'tesseract {path} /tmp/out -l eng'.encode(),ctypes.byref(n),ctypes.byref(v),ctypes.byref(e))
 print(label,'argument count:',n.value)
 G.g_strfreev(v)
PY
unquoted argument count: 7
quoted argument count: 5

In TesseractTrigger.vala, quote file_path, out_path, and lang with GLib.Shell.quote() before passing the command to Process.spawn_command_line_sync(), or pass an argument array to Process.spawn_sync(). Until that is fixed, use your desktop's copy screenshot to clipboard action and then Get from Clipboard, which avoids creating the extra capture file. If your portal's returned path has no spaces, run TextSnatcher from a terminal and check the printed Error is ... status is ... line; the same on-screen message also covers other Tesseract failures.