null pointer dereferenced when "file" is given a bogus path

[llvmbot]

Bugzilla Link	9053
Resolution	FIXED
Resolved on	Jan 25, 2011 15:32
Version	unspecified
OS	MacOS X
Attachments	Checks to see if the string is empty before using it
Reporter	LLVM Bugzilla Contributor

Extended Description

I accidentally used lldb's "file" command with a bogus path.

Instead of:

file /Users/kenryall/Source/HW_XCode/build/Debug/HW_XCode

I gave it:

file file://localhost/Users/kenryall/Source/HW_XCode/build/Debug/HW_XCode

This caused a null pointer to be used in FileSpec::ResolveExecutableLocation.

The attached patch fixes this problem.

[llvmbot]

I fixed this in a slightly different way. ConstString has two C string accessors:
const char * ConstString::AsCString(const char *value_if_empty);
const char * ConstString::GetCString(); // Can return NULL

I used the latter with the fix I submitted.

Committed revision 124231.