Crash when reading CityGML file with GML driver

[Kosta]

When opening the following unzipped file (e.g. using ogrinfo) the GML driver is crashing: ​https://dl.dropbox.com/u/1510901/Test-CityGml-LandXplorer.gml.zip

[Kosta]

A simple fix would be to change line 125 of gmlpropertydefn.cpp from:

if( *pszValue == '\0' )

to

if( !pszValue

!*pszValue )

in order to avoid a NULL pointer access in cases pszValue is NULL.

Not sure, if this is the right fix or if there is another issue and (pszValue == NULL) should never happen there...

[Kosta]

if( !pszValue !*pszValue )

There needs to be an "OR" in between which gets eaten from the WIKI, not sure how to format that in the correct way...

[Kosta]

After applying the suggested fix another crash happens, when starting to access the individual features of that file. This time due to a NULL pointer access in line 1944 of file ogrfeature.cpp.

I would suggest to add these lines at line 1935 in that file:

    if( !pszValue )
    {
        UnsetField( iField );
        return;
    }    

[Kosta]

I created a GitHub pull request for my proposed changes...

[Even Rouault]

I wouldn't fix the bug like that. IMHO, SetFeature() should never been passed a NULL pointer, so some tracking would be needed to identify which caller tries to patch the NULL pointer.

[Even Rouault]

Fixed in trunk (r25579) and branches/1.9 (r25580)