snapshot/mac: MachOImageAnnotationsReader test shouldn’t crash with a nullptr ProcessReader::Module

snapshot/mac/process_reader_test.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 522 matching lines @@
   // dyld_image_count doesn’t include an entry for dyld itself, but |modules|
   // does.
   ASSERT_EQ(dyld_image_count + 1, modules.size());
 
   for (uint32_t index = 0; index < dyld_image_count; ++index) {
     SCOPED_TRACE(base::StringPrintf(
         "index %u, name %s", index, modules[index].name.c_str()));
 
     const char* dyld_image_name = _dyld_get_image_name(index);
     EXPECT_EQ(dyld_image_name, modules[index].name);
+    ASSERT_TRUE(modules[index].reader);
     EXPECT_EQ(
         reinterpret_cast<mach_vm_address_t>(_dyld_get_image_header(index)),
         modules[index].reader->Address());
 
     if (index == 0) {
       // dyld didn’t load the main executable, so it couldn’t record its
       // timestamp, and it is reported as 0.
       EXPECT_EQ(0, modules[index].timestamp);
     } else {
       // Hope that the module didn’t change on disk.
       struct stat stat_buf;
       int rv = stat(dyld_image_name, &stat_buf);
       EXPECT_EQ(0, rv) << ErrnoMessage("stat");
       if (rv == 0) {
         EXPECT_EQ(stat_buf.st_mtime, modules[index].timestamp);
       }
     }
   }
 
   size_t index = modules.size() - 1;
   EXPECT_EQ("/usr/lib/dyld", modules[index].name);
 
   // dyld didn’t load itself either, so it couldn’t record its timestamp, and it
   // is also reported as 0.
   EXPECT_EQ(0, modules[index].timestamp);
 
   const struct dyld_all_image_infos* dyld_image_infos =
       _dyld_get_all_image_infos();
   if (dyld_image_infos->version >= 2) {
+    ASSERT_TRUE(modules[index].reader);
     EXPECT_EQ(
         reinterpret_cast<mach_vm_address_t>(
             dyld_image_infos->dyldImageLoadAddress),
         modules[index].reader->Address());
   }
 }
 
 class ProcessReaderModulesChild final : public MachMultiprocess {
  public:
   ProcessReaderModulesChild() : MachMultiprocess() {}
@@ skipping 27 matching lines @@
       CheckedReadFile(
           read_handle, &expect_name_length, sizeof(expect_name_length));
 
       // The NUL terminator is not read.
       std::string expect_name(expect_name_length, '\0');
       CheckedReadFile(read_handle, &expect_name[0], expect_name_length);
       EXPECT_EQ(expect_name, modules[index].name);
 
       mach_vm_address_t expect_address;
       CheckedReadFile(read_handle, &expect_address, sizeof(expect_address));
+      ASSERT_TRUE(modules[index].reader);
       EXPECT_EQ(expect_address, modules[index].reader->Address());
 
       if (index == 0 || index == modules.size() - 1) {
         // dyld didn’t load the main executable or itself, so it couldn’t record
         // these timestamps, and they are reported as 0.
         EXPECT_EQ(0, modules[index].timestamp);
       } else {
         // Hope that the module didn’t change on disk.
         struct stat stat_buf;
         int rv = stat(expect_name.c_str(), &stat_buf);
@@ skipping 57 matching lines @@
 };
 
 TEST(ProcessReader, ChildModules) {
   ProcessReaderModulesChild process_reader_modules_child;
   process_reader_modules_child.Run();
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace crashpad