--- src/core/SkReadBuffer.cpp.orig
+++ src/core/SkReadBuffer.cpp
@@ -127,12 +127,12 @@
     return this->readInt();
 }
 
-uint8_t SkReadBuffer::peekByte() {
-    if (this->available() <= 0) {
+uint8_t SkReadBuffer::peekByte(size_t offs) {
+    if (this->available() <= offs) {
         fError = true;
         return 0;
     }
-    return *((const uint8_t*)fCurr);
+    return ((const uint8_t*)fCurr)[offs];
 }
 
 bool SkReadBuffer::readPad32(void* buffer, size_t bytes) {
@@ -488,7 +488,15 @@
         }
         factory = fFactoryArray[index];
     } else {
-        if (this->peekByte() != 0) {
+        // The writer stores a dictionary index as (index << 8) so that the first byte written
+        // is zero and can act as a "this is an index, not a string" sentinel.  The first byte
+        // written is the low byte of the 32-bit word on little endian, the high byte on big.
+#ifdef SK_CPU_BENDIAN
+        constexpr size_t kSentinelByte = 3;
+#else
+        constexpr size_t kSentinelByte = 0;
+#endif
+        if (this->peekByte(kSentinelByte) != 0) {
             // If the first byte is non-zero, the flattenable is specified by a string.
             size_t ignored_length;
             if (const char* name = this->readString(&ignored_length)) {