From ddb36767a5002f3e4d25f9f4b93e61a7deb5f4e3 Mon Sep 17 00:00:00 2001
From: Romain Deltour <rdeltour@gmail.com>
Date: Sun, 22 Dec 2024 00:50:15 +0100
Subject: [PATCH] fix: reject unknown `epub:` attributes in SVG

The spec only requires SVG to be well-formed, but one can argue that
attributes in the EPUB namespace can only be defined by the EPUB specs
and therefore should still be validated.

For instance, EPUB already specifies where `epub:type` is allowed in SVG,
as a normative statement.

This commit updates the persmissive SVG schema to reject all attributes
in the `http://www.idpf.org/2007/ops` namespace except the known ones.
---
 .../epubcheck/schema/30/mod/epub-svg-forgiving-inc.rnc     | 6 ++++--
 .../epub3/06-content-document/content-document-svg.feature | 7 +++++++
 .../files/unknown-epub-attribute-error.svg                 | 7 +++++++
 3 files changed, 18 insertions(+), 2 deletions(-)
 create mode 100644 src/test/resources/epub3/06-content-document/files/unknown-epub-attribute-error.svg

diff --git a/src/main/resources/com/adobe/epubcheck/schema/30/mod/epub-svg-forgiving-inc.rnc b/src/main/resources/com/adobe/epubcheck/schema/30/mod/epub-svg-forgiving-inc.rnc
index c08a94acc..94b714f77 100644
--- a/src/main/resources/com/adobe/epubcheck/schema/30/mod/epub-svg-forgiving-inc.rnc
+++ b/src/main/resources/com/adobe/epubcheck/schema/30/mod/epub-svg-forgiving-inc.rnc
@@ -19,7 +19,9 @@
   svg =
     element svg { svg.inner & svg.attrs }
   svg.attrs =
-    ( svg.epubtype.allowed.attrs )
+    ( svg.epubtype.allowed.attrs
+      & epub.prefix.attr.ns?
+    )
   svg.inner =
     ( svg.any.inner )
 
@@ -35,7 +37,7 @@
   svg.generic.attr =
     attribute *
       - ( id
-        | epub:type
+        | epub:*
         ) { text }
 
   # Attribute list of elements where `epub:type` is allowed
diff --git a/src/test/resources/epub3/06-content-document/content-document-svg.feature b/src/test/resources/epub3/06-content-document/content-document-svg.feature
index 413677a93..20f65df46 100644
--- a/src/test/resources/epub3/06-content-document/content-document-svg.feature
+++ b/src/test/resources/epub3/06-content-document/content-document-svg.feature
@@ -51,6 +51,13 @@ Feature: EPUB 3 — Content Documents — SVG
     And the message contains '"epub:type" not allowed'
     And no other errors or warnings are reported
 
+  Scenario: Report an unknown `epub:*` attribute used in SVG
+    Given the reporting level is set to usage
+    When checking document 'unknown-epub-attribute-error.svg'
+    Then error RSC-005 is reported
+    And the message contains '"epub:unknown" not allowed'
+    And no other errors or warnings are reported
+
   
   ### 6.2.2 SVG requirements
 
diff --git a/src/test/resources/epub3/06-content-document/files/unknown-epub-attribute-error.svg b/src/test/resources/epub3/06-content-document/files/unknown-epub-attribute-error.svg
new file mode 100644
index 000000000..aee630744
--- /dev/null
+++ b/src/test/resources/epub3/06-content-document/files/unknown-epub-attribute-error.svg
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:epub="http://www.idpf.org/2007/ops" epub:unknown=""
+	version="1.1">
+	<title>Test</title>
+	<desc>Description</desc>
+	<circle r="10"/>
+</svg>