commit bc490c9c7c3d434169c9de83a90e72b69586ce3e
author Pirama Arumuga Nainar <pirama@google.com> Mon Mar 11 16:52:07 2019 -0700
committer android-build-merger <android-build-merger@google.com> Mon Mar 11 16:52:07 2019 -0700
tree e2034b36c1fe365add09cd313783d889a70616e5
parent 4219eef6ec06af2ed7311110b897fcdbe6406a9d
parent 7917dc5aa91ba7153dbd0661df327286360b101d

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

Change-Id: I3003c327899f0d6712f7c5723bc08dd666045b67

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) {