Prevent crashes in mime_util_xdg.

base/nix/mime_util_xdg.cc

Index: base/nix/mime_util_xdg.cc
diff --git a/base/nix/mime_util_xdg.cc b/base/nix/mime_util_xdg.cc
index 030c30c11f6559361aed3757461a2d89d4268b95..33519bf42f42ffb512ebfa748f6765a511f46d26 100644
--- a/base/nix/mime_util_xdg.cc
+++ b/base/nix/mime_util_xdg.cc
@@ -588,6 +588,7 @@ namespace base {
 namespace nix {
 
 std::string GetFileMimeType(const FilePath& filepath) {
+  if (filepath.empty()) return "";

[brettw, 2012/08/16 03:37:34]

Don't use single-line style except in unusual cases. Also, return std::string()
is more efficient and is semantically correct, otherwise it calls std::string's
constructor with an empty string which it has to interpret.

[benjhayden, 2012/08/16 14:33:35]

Done.

   base::ThreadRestrictions::AssertIOAllowed();
   base::AutoLock scoped_lock(g_mime_util_xdg_lock.Get());
   return xdg_mime_get_mime_type_from_file_name(filepath.value().c_str());
@@ -625,7 +626,9 @@ FilePath GetMimeIcon(const std::string& mime_type, size_t size) {
   std::string icon_name;
   FilePath icon_file;
 
-  {
+  if (mime_type.empty()) {
+    icon_name = "";

[brettw, 2012/08/16 03:37:34]

Can't this be removed and you put the else case in an if (!mime_type.empty())?

[benjhayden, 2012/08/16 14:33:35]

Done.

+  } else {
     base::AutoLock scoped_lock(g_mime_util_xdg_lock.Get());
     const char *icon = xdg_mime_get_icon(mime_type.c_str());
     icon_name = std::string(icon ? icon : "");