commit dbbe8531b991b78df845a13ae24ea0c94570a9c4
author Pirama Arumuga Nainar <pirama@google.com> Mon Mar 11 17:17:04 2019 -0700
committer android-build-merger <android-build-merger@google.com> Mon Mar 11 17:17:04 2019 -0700
tree ff655e2a1adc1e2092e746d0fa2d9c0bd83d1469
parent 41958159fb6c8e687c493f195b5e6ef3641da42c
parent bc490c9c7c3d434169c9de83a90e72b69586ce3e

Merge "Support zero-length mapped files" am: 2009e32008 am: 747e647bd3
am: 4c88d1aec3

Change-Id: I2f19669b7f6d7224497c7c44857b8ed9b2d4e13f

base/mapped_file.cpp

diff --git a/base/mapped_file.cpp b/base/mapped_file.cpp
index faa845d..7c65dc3 100644
--- a/base/mapped_file.cpp
+++ b/base/mapped_file.cpp
@@ -41,7 +41,14 @@
   HANDLE handle =
       CreateFileMapping(reinterpret_cast<HANDLE>(_get_osfhandle(fd)), nullptr,
                         (prot & PROT_WRITE) ? PAGE_READWRITE : PAGE_READONLY, 0, 0, nullptr);
-  if (handle == nullptr) return nullptr;
+  if (handle == nullptr) {
+    // http://b/119818070 "app crashes when reading asset of zero length".
+    // Return a MappedFile that's only valid for reading the size.
+    if (length == 0) {
+      return std::unique_ptr<MappedFile>(new MappedFile{nullptr, 0, 0, nullptr});
+    }
+    return nullptr;
+  }
   void* base = MapViewOfFile(handle, (prot & PROT_WRITE) ? FILE_MAP_ALL_ACCESS : FILE_MAP_READ, 0,
                              file_offset, file_length);
   if (base == nullptr) {