Adress 4479

Ensure that layer states are correctly reported and can selectively be set.

Author: JorjMcKie

tests/resources/test-4479.pdf

@@ -0,0 +1,21 @@
+import pymupdf
+
+
+def test_4479():
+    if pymupdf.mupdf_version_tuple < (1, 26, 0):
+        print("Skipping test_4479: requires MuPDF 1.26.0 or later")
+        return
+    path = os.path.abspath(f"{__file__}/../../tests/resources/test-4479.pdf")
+    doc = pymupdf.open(path)
+
+    for layer in doc.layer_ui_configs():
+        if layer["text"] == "layer_2":
+            assert not layer["on"]
+        else:
+            assert layer["on"]
+    doc.set_layer_ui_config("layer_7", action=pymupdf.PDF_OC_TOGGLE)
+    for layer in doc.layer_ui_configs():
+        if layer["text"] in ("layer_2", "layer_7"):
+            assert not layer["on"]
+        else:
+            assert layer["on"]