tests/: added test_4712().

Author: julian-smith-artifex-com

tests/resources/test_4712_a.pdf

@@ -2115,3 +2115,14 @@ def test_4702():
             _ = document.xref_object(xref)
     wt = pymupdf.TOOLS.mupdf_warnings()
     assert wt == 'repairing PDF document'
+
+
+def test_4712():
+    path_a = os.path.normpath(f'{__file__}/../../tests/resources/test_4712_a.pdf')
+    path_b = os.path.normpath(f'{__file__}/../../tests/resources/test_4712_b.pdf')
+    doc1 = pymupdf.open(path_a)
+    for i in range(6):
+        doc1.load_page(i).get_pixmap()
+    doc2 = pymupdf.open(path_b)
+    for i in range(6):
+        doc2.load_page(i).get_pixmap()