The constructor of nsSpecialSystemDirectory constructs its base class, nsFileSpec, like nsFileSpec(null). This calls the ctor nsFileSpec::nsFileSpec(const char* inNativePathString, PRBool inCreateDirs) which is not designed to handle a null inNativePathString, and ends up calling strlen and strchr on *nil on Mac.

I think the correct fix is to check for null input strings in nsFileSpec: < mError = NS_FILE_RESULT( < MacFileHelpers::FSSpecFromPathname( < inNativePathString, < mSpec, inCreateDirs)); < if (mError == NS_FILE_RESULT(fnfErr)) < mError = NS_OK; < --- > if (inNativePathString) > { > mError = NS_FILE_RESULT(MacFileHelpers::FSSpecFromPathname( > inNativePathString, > mSpec, inCreateDirs)); > if (mError == NS_FILE_RESULT(fnfErr)) > mError = NS_OK; > } > else > { > mError = NS_ERROR_NOT_INITIALIZED; > } > and < mError = NS_FILE_RESULT( < MacFileHelpers::FSSpecFromPathname(inString, mSpec, true)); < if (mError == NS_FILE_RESULT(fnfErr)) < mError = NS_OK; --- > if (inString) > { > mError = NS_FILE_RESULT(MacFileHelpers::FSSpecFromPathname(inString, mSpec, true)); > if (mError == NS_FILE_RESULT(fnfErr)) > mError = NS_OK; > } > else > { > mError = NS_ERROR_NOT_INITIALIZED; > }

changes look good. check um in!

I'll take this

Fix checked in to nsFileSpecMac.cpp

marking verified and setting milestone