patterns: Parse supplementary volume descriptors

patterns/iso.hexpat

@@ -99,6 +99,15 @@ struct DirectoryRecord {
   padding[$ % 2];
 };
 
+fn GetSupplementaryEncoding() {
+  const u128 escapeSequencesOffset = 89 - 8;
+
+  str encoding = std::mem::read_string($ + escapeSequencesOffset, 0x20);
+  return encoding == "%/@\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
+      || encoding == "%/C\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
+      || encoding == "%/E\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
+};
+
 struct VolumeDescriptor {
   VolumeDescriptorTypes type;
   char id[5];
@@ -120,7 +129,7 @@ struct VolumeDescriptor {
     char setId[0x80];
     char publisherId[0x80];
     char preparerId[0x80];
-    char applicationId[0x80];
+  } else if (type == VolumeDescriptorTypes::SupplementaryVolume && GetSupplementaryEncoding()) {
     char copyrightFileId[0x25];
     char abstractFileId[0x25];
     char bibliographicFileId[0x25];
@@ -129,6 +138,34 @@ struct VolumeDescriptor {
     StrDateFormat expirationTime[[format("FormatStrDate")]];
     StrDateFormat effectiveTime[[format("FormatStrDate")]];
     u8 fileStructVersion;
+  } else if (type == VolumeDescriptorTypes::SupplementaryVolume) {
+    u8 flags;
+    be char16 systemId[0x10];
+    be char16 volumeId[0x10];
+    padding[8];
+    di32 spaceSize;
+    u8 escapeSequences[0x20];
+    di16 setSize;
+    di16 sequenceNumber;
+    di16 logicalBlockSize;
+    di32 pathTableSize;
+    PathTablePtr pathTableOffset;
+    DirectoryRecord rootDir;
+    be char16 setId[0x40];
+    be char16 publisherId[0x40];
+    be char16 preparerId[0x40];
+    be char16 applicationId[0x40];
+    be char16 copyrightFileId[0x12];
+    padding[1];
+    be char16 abstractFileId[0x12];
+    padding[1];
+    be char16 bibliographicFileId[0x12];
+    padding[1];
+    StrDateFormat creationTime[[format("FormatStrDate")]];
+    StrDateFormat modificationTime[[format("FormatStrDate")]];
+    StrDateFormat expirationTime[[format("FormatStrDate")]];
+    StrDateFormat effectiveTime[[format("FormatStrDate")]];
+    u8 fileStructVersion;
   }
   padding[0x800 - $ % 0x800];
 };