Fetching HFS files now gives you a AppleSingle file with both data and resource

forks.

lib/vfs/applesingle.cc

@@ -0,0 +1,78 @@
+#include "lib/globals.h"
+#include "lib/bytes.h"
+#include "lib/vfs/applesingle.h"
+
+static constexpr uint32_t APPLESINGLE_MAGIC = 0x00051600;
+static constexpr uint32_t APPLESINGLE_VERSION = 0x00020000;
+
+void AppleSingle::parse(const Bytes& bytes)
+{
+    ByteReader br(bytes);
+    if (br.read_be32() != APPLESINGLE_MAGIC)
+        throw InvalidFileException();
+    if (br.read_be32() > APPLESINGLE_VERSION)
+        throw InvalidFileException();
+
+    br.skip(16);
+    int entries = br.read_be16();
+    for (int i = 0; i < entries; i++)
+    {
+        uint32_t entryType = br.read_be32();
+        uint32_t offset = br.read_be32();
+        uint32_t length = br.read_be32();
+
+        switch (entryType)
+        {
+            case 1:
+                data = bytes.slice(offset, length);
+                break;
+
+            case 2:
+                rsrc = bytes.slice(offset, length);
+                break;
+
+            case 9:
+            {
+            	Bytes finderinfo = bytes.slice(offset, length);
+            	type = finderinfo.slice(0, 4);
+            	creator = finderinfo.slice(4, 4);
+                break;
+            }
+
+            default:
+                break;
+        }
+    }
+}
+
+Bytes AppleSingle::render()
+{
+    Bytes result;
+    ByteWriter bw(result);
+
+    bw.write_be32(APPLESINGLE_MAGIC);
+    bw.write_be32(APPLESINGLE_VERSION);
+    bw.append(Bytes(16)); /* padding */
+    bw.write_be16(3);     /* number of entries */
+
+    bw.write_be32(9);    /* finder info */
+    bw.write_be32(0x3e); /* finder info offset */
+    bw.write_be32(32);   /* finder info length */
+
+    bw.write_be32(1);           /* data fork */
+    bw.write_be32(OVERHEAD);    /* data fork offset */
+    bw.write_be32(data.size()); /* data fork length */
+
+    bw.write_be32(2);                      /* resource fork */
+    bw.write_be32(OVERHEAD + data.size()); /* resource fork offset */
+    bw.write_be32(rsrc.size());            /* resource fork length */
+
+    bw.append(type.slice(0, 4));
+    bw.append(creator.slice(0, 4));
+    bw.append(Bytes(32 - 8));
+
+    bw.append(data);
+    bw.append(rsrc);
+
+    return result;
+}