PDFBOX-5733: assign extensionLookupType to lookupType and check that …

…they remain the same git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1914537 13f79535-47bb-0310-9956-ffa450edef68
apache · Dec 11, 2023 · 924dabe · 924dabe
1 parent 5e468b4
commit 924dabe
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/fontbox/src/main/java/org/apache/fontbox/ttf/GlyphSubstitutionTable.java b/fontbox/src/main/java/org/apache/fontbox/ttf/GlyphSubstitutionTable.java
@@ -343,6 +343,16 @@ private LookupTable readLookupTable(TTFDataStream data, long offset) throws IOEx
                 long baseOffset = data.getCurrentPosition();
                 int substFormat = data.readUnsignedShort(); // always 1
                 int extensionLookupType = data.readUnsignedShort();
+                if (lookupType != 7 && lookupType != extensionLookupType)
+                {
+                    // "If a lookup table uses extension subtables, then all of the extension
+                    //  subtables must have the same extensionLookupType"
+                    LOG.error("extensionLookupType changed from {} to {}",
+                            lookupType, extensionLookupType);
+                    data.seek(baseOffset + 8);
+                    continue;
+                }
+                lookupType = extensionLookupType;
                 long extensionOffset = data.readUnsignedInt();
                 if (substFormat != 1)
                 {