Fix "cannot open display: wayland-0" error in Wayland #1

xsanecli.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 
 #   GIMP 3.0 plug-in for scanning via XSane
-#   Copyright (C) 2024  Lee Yingtong Li (RunasSudo)
+#   Copyright (C) 2024-2025  Lee Yingtong Li (RunasSudo)
 #
 #   This program is free software: you can redistribute it and/or modify
 #   it under the terms of the GNU General Public License as published by
@@ -28,36 +28,54 @@ import sys
 import tempfile
 
 DEVICE_NAME = None  # e.g. DEVICE_NAME = 'escl:http://10.0.0.1:80'
+SCAN_MULTIPLE = True
 
 def xsanecli_run(procedure, config, run_data, *args):
 	# Get temporary directory
 	tempdir = tempfile.mkdtemp('gimp-plugin-xsanecli')
 	png_out = os.path.join(tempdir, 'out.png')
 	
+	xsane_env = dict(os.environb)
+	
+	# Fix if DISPLAY is set to a Wayland display
+	# For some reason, in Wayland contexts, DISPLAY is clobbered with WAYLAND_DISPLAY when Python is called
+	# This causes "Gtk-WARNING: cannot open display: wayland-0"
+	if b'DISPLAY' in xsane_env and xsane_env[b'DISPLAY'].startswith(b'wayland-'):
+		# Recover the original environment from GIMP (the parent process)
+		with open('/proc/{}/environ'.format(os.getppid()), 'rb') as f:
+			orig_env = {var[:var.index(b'=')]: var[var.index(b'=')+1:] for var in f.read().split(b'\0') if var}
+		
+		if b'DISPLAY' in orig_env:
+			xsane_env[b'DISPLAY'] = orig_env[b'DISPLAY']
+	
 	# Open XSane
 	args = ['xsane', '--save', '--no-mode-selection', '--force-filename', png_out, '--print-filenames'] + ([DEVICE_NAME] if DEVICE_NAME else [])
-	proc = subprocess.Popen(args, stdout=subprocess.PIPE, encoding='utf-8')
+	proc = subprocess.Popen(args, stdout=subprocess.PIPE, encoding='utf-8', env=xsane_env)
 	
-	# Wait until XSane prints the name of the scanned file, indicating scanning is finished
-	# This blocks Python but that is ok because GIMP UI is not affected
-	result = proc.stdout.readline().strip()
+	while True:
+		# Wait until XSane prints the name of the scanned file, indicating scanning is finished
+		# This blocks Python but that is ok because GIMP UI is not affected
+		result = proc.stdout.readline().strip()
+		
+		if result == '':
+			# XSane was closed
+			break
+		
+		if result != 'XSANE_IMAGE_FILENAME: ' + png_out:
+			Gimp.message('Unexpected XSane result')
+			return Gimp.ValueArray.new_from_values([GObject.Value(Gimp.PDBStatusType, Gimp.PDBStatusType.EXECUTION_ERROR)])
+		
+		# Open image
+		image = Gimp.file_load(Gimp.RunMode.NONINTERACTIVE, Gio.File.new_for_path(png_out))
+		Gimp.Display.new(image)
+		
+		# Remove temporary files
+		os.unlink(png_out)
+		
+		if not SCAN_MULTIPLE:
+			proc.terminate()
+			break
 	
-	proc.terminate()
-	
-	if result == '':
-		# XSane was closed
-		return Gimp.ValueArray.new_from_values([GObject.Value(Gimp.PDBStatusType, Gimp.PDBStatusType.CANCEL)])
-	
-	if result != 'XSANE_IMAGE_FILENAME: ' + png_out:
-		Gimp.message('Unexpected XSane result')
-		return Gimp.ValueArray.new_from_values([GObject.Value(Gimp.PDBStatusType, Gimp.PDBStatusType.EXECUTION_ERROR)])
-	
-	# Open image
-	image = Gimp.file_load(Gimp.RunMode.NONINTERACTIVE, Gio.File.new_for_path(png_out))
-	Gimp.Display.new(image)
-	
-	# Remove temporary files
-	os.unlink(png_out)
 	os.rmdir(tempdir)
 	
 	return Gimp.ValueArray.new_from_values([GObject.Value(Gimp.PDBStatusType, Gimp.PDBStatusType.SUCCESS), GObject.Value(Gimp.Image.__gtype__, image)])