KmzFile's ReadKML() always returns an empty string

[MeLikeyCode]

KmzFile* kmzFile = KmzFile::OpenFromString(someString); // some string checked to make sure is kmz
std::string kmlString;
kmzFile->ReadKml(&kmlString); // after execution, kmlString is always empty ("") and false returned.

Again, I have checked to make sure "someString" really is kmz data, and that there IS a doc.kml file inside the kmz. Why is the ReadKml function STILL returning false and putting an empty string as output?

[rashadkm]

can you provide a test case or share the contents of someString ?

[MeLikeyCode]

Hi rashadkm, thank you very much for your response! I will try to upload the contents of the string as soon as I can (I cannot at the moment). When I use KmzFile::OpenFromFile, it works but OpenFromString does not work. So I must be doing something wrong converting the file to string?

Here is what works:
std::string kmlString;
KmzFile* kmzFile = KmzFile::OpenFromFile("test.kmz");
kmzfile->ReadKml(&kmlString); // contents of kmlString is the default .kml flie in the .kmz - works!

Here is what doesn't work:
std::ifstream fileStream("test.kmz");
std::stringstream stringStream;
stringStream << fileStream.rdbuf();
std::string fileString = stringStream.str();

KmzFile* kmzFile = KmzFile::OpenFromString(fileString);
kmzFile->ReadKml(&kmlString); //kmlString ends up being just an empty ("") string!

Do you have any ideas as to why the above solution works while the below solution doesn't?