Tweak PathProviderPosix's FILE_EXE and FILE_MODULE handling on FreeBSD.

base/base_paths_linux.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/base_paths.h"
 
 #include <ostream>
 #include <string>
 
 #include "build/build_config.h"
@@ skipping 32 matching lines @@
       if (!file_util::ReadSymbolicLink(FilePath(kSelfExe), &bin_dir)) {
         NOTREACHED() << "Unable to resolve " << kSelfExe << ".";
         return false;
       }
       *result = bin_dir;
       return true;
 #elif defined(OS_FREEBSD)
       int name[] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
       char bin_dir[PATH_MAX + 1];
       size_t length = sizeof(bin_dir);
+      // Upon return, |length| is the number of bytes written to |bin_dir|
+      // including the string terminator.
       int error = sysctl(name, 4, bin_dir, &length, NULL, 0);
-      if (error < 0 || length == 0 || strlen(bin_dir) == 0) {
+      if (error < 0 || length <= 1) {
         NOTREACHED() << "Unable to resolve path.";
         return false;
       }
-      bin_dir[strlen(bin_dir)] = 0;
-      *result = FilePath(bin_dir);
+      *result = FilePath(FilePath::StringType(bin_dir, length - 1));
       return true;
 #elif defined(OS_SOLARIS)
       char bin_dir[PATH_MAX + 1];
       if (realpath(getexecname(), bin_dir) == NULL) {
         NOTREACHED() << "Unable to resolve " << getexecname() << ".";
         return false;
       }
       *result = FilePath(bin_dir);
       return true;
 #elif defined(OS_OPENBSD)
@@ skipping 51 matching lines @@
       scoped_ptr<base::Environment> env(base::Environment::Create());
       FilePath cache_dir(base::nix::GetXDGDirectory(env.get(), "XDG_CACHE_HOME",
                                                     ".cache"));
       *result = cache_dir;
       return true;
   }
   return false;
 }
 
 }  // namespace base