Merge "Fix A/B update fail for 32-bit devices"

am: 0474f1be45

Change-Id: I503cda9f3e4c0b034c22cdf7bb9c557bf52147f5

bsdiff.gyp

@@ -27,6 +27,9 @@
       # "bsdiff/...".
       '<(platform2_root)/../aosp/external',
     ],
+    'defines': [
+      '_FILE_OFFSET_BITS=64',
+    ],
   },
   'targets': [
     # bsdiff static library

file.cc

@@ -64,11 +64,7 @@ bool File::Seek(off_t pos) {
     errno = EBADF;
     return false;
   }
-  // fseek() uses a long value for the offset which could be smaller than off_t.
-  if (pos > std::numeric_limits<long>::max()) {
-    errno = EOVERFLOW;
-    return false;
-  }
+
   off_t newpos = lseek(fd_, pos, SEEK_SET);
   if (newpos < 0)
     return false;

include/bsdiff/file_interface.h

@@ -12,6 +12,9 @@
 
 #include "bsdiff/common.h"
 
+static_assert(sizeof(off_t) == sizeof(int64_t),
+              "off_t must be a 64-bit number, use -D_FILE_OFFSET_BITS=64");
+
 namespace bsdiff {
 
 class BSDIFF_EXPORT FileInterface {