crash when creating an empty shapefile and insert a new feature into it

[mhugent@…]

Hi, I'm not sure if this is a bug in OGR or in my program. What i try to do is to create an empty shapefile and later to open this shapefile and insert features into it.

When i try to add the feature, a crash happens. Also i noticed that a field, which i created on the empty shapefile is not recognised when the empty layer is opened.

Below is my source code and the debugger backtrace after the crash.

A .tgz of the created files (.shp,.dbf,etc.) befor adding a feature is on ​ftp://ftp.geo.unizh.ch/pub/mhugent/newlayertest.tgz

//create an empty layer and add a field to it 
OGRwkbGeometryType geomtype=(OGRwkbGeometryType)((int)vectortype); 
    QString mOutputFormat = "ESRI Shapefile"; 
    QString mOutputFileName = uri; 
#ifdef WIN32  
    QString 
outname=mOutputFileName.mid(mOutputFileName.findRev("\\")+1,mOutputFileName.length()); 
#else 
    QString 
outname=mOutputFileName.mid(mOutputFileName.findRev("/")+1,mOutputFileName.length()); 
#endif 
    OGRSFDriverRegistrar* driverregist = OGRSFDriverRegistrar::GetRegistrar(); 
     
    if(driverregist==0) 
    { 
	return false; 
    } 
    OGRSFDriver* driver = driverregist->GetDriverByName(mOutputFormat); 
    if(driver==0) 
    { 
	return false; 
    } 
    OGRDataSource* datasource = driver->CreateDataSource(mOutputFileName,NULL); 
    if(datasource==0) 
    { 
	return false; 
    } 
 
    OGRSpatialReference reference; 
    OGRLayer* layer = datasource->CreateLayer(outname.latin1
(),&reference,geomtype,NULL); 
    if(layer==0) 
    { 
	return false; 
    } 
 
    OGRFieldDefn fielddef("dummy",OFTReal); 
    fielddef.SetWidth(1); 
    fielddef.SetPrecision(1); 
    if(layer->CreateField(&fielddef,FALSE)!=OGRERR_NONE) 
    { 
	return false; 
    } 

The debugger output when inserting a new feature afterwards:

Program received signal SIGSEGV, Segmentation fault. 
[Switching to Thread 1091298272 (LWP 25403)] 
0x40a70218 in DBFGetRecordCount () from /usr/local/lib/libgdal.so.1 
(gdb) backtrace 
#0  0x40a70218 in DBFGetRecordCount () from /usr/local/lib/libgdal.so.1 
#1  0x40b0992f in SHPWriteOGRFeature () from /usr/local/lib/libgdal.so.1 
#2  0x40af4936 in OGRShapeLayer::CreateFeature () 
from /usr/local/lib/libgdal.so.1 
#3  0x41923027 in QgsShapeFileProvider::commitFeature (this=0x85a0668, 
f=0x85f7cb0) at qgsshapefileprovider.cpp:820 
#4  0x41922e14 in QgsShapeFileProvider::commitChanges (this=Variable "this" is 
not available. 
) at stl_list.h:167

Marco

[warmerdam]

Mateusz,

I'd like you to try to reproduce this problem and see if it still exists. If so, lets fix it. If the fix is straight forward it can go into 1.4.2. If it seems tricky, perhaps just trunk.

[Mateusz Łoskot]

Unfortunately, due to the fact this issue as reported long time ago, the file exposed to under following URL is no longer available:

​ftp://ftp.geo.unizh.ch/pub/mhugent/newlayertest.tgz

I'll try to reproduce the problem using my own empty shapefile and the issue description.

[Mateusz Łoskot]

Makefile for building test.cpp under Unix

[Mateusz Łoskot]

Test program creating empty Shapefile

[Mateusz Łoskot]

Here I test the first part of the problem. I'm trying to reproduce very similar program as pasted in the report above and run.

NOTE: The program above looks as incomplete - there is no CreateFeature() call. Also, my first test - test.cpp - does also not call CreateFeature but just generates empty shapefile.

• Compile test program

mloskot:~/dev/gdal/bugs/641$ make 
g++ -g -I/home/mloskot/dev/gdal/_svn/trunk/gdal \
-I/home/mloskot/dev/gdal/_svn/trunk/gdal/port \
-I/home/mloskot/dev/gdal/_svn/trunk/gdal/gcore \
-I/home/mloskot/dev/gdal/_svn/trunk/gdal/ogr  \
-I/home/mloskot/dev/gdal/_svn/trunk/gdal/ogr/ogrsf_frmts  test.cpp -o test  \
-L/home/mloskot/dev/gdal/_svn/trunk/gdal -lgdal

• Run the program to create empty.shp data

mloskot:~/dev/gdal/bugs/641$ ls
Makefile  test  test.cpp

mloskot:~/dev/gdal/bugs/641$ ./test

mloskot:~/dev/gdal/bugs/641$ ls
empty.dbf  empty.prj  empty.shp  empty.shx  Makefile  test  test.cpp

• Investigate the results with Shapelib utilities

mloskot:~/dev/gdal/bugs/641$ shpdump empty.shp
Shapefile Type: Point   # of Shapes: 0

File Bounds: (       0.000,       0.000,0,0)
         to  (       0.000,       0.000,0,0)

mloskot:~/dev/gdal/bugs/641$ dbfdump -h empty.shp
Field 0: Type=Double, Title=`dummy', Width=1, Decimals=1
dummy 

• Investigate the results using ogrinfo

mloskot:~/dev/gdal/bugs/641$ ogrinfo -ro empty.shp empty
OGR: OGROpen(empty.shp/0x804e550) succeeded as ESRI Shapefile.
INFO: Open of `empty.shp'
      using driver `ESRI Shapefile' successful.
OGR: GetLayerCount() = 1


Layer name: empty
Geometry: Point
Feature Count: 0
Extent: (0.000000, 0.000000) - (0.000000, 0.000000)
Layer SRS WKT:
(unknown)
dummy: Real (1.1)

This part of the problem works.

[Mateusz Łoskot]

Test program adding feature to empty Shapefile

[Mateusz Łoskot]

Here I test adding sample feature to empty shapefile created using test.cpp program. The program adding a feature is called test2.cpp

• Compile all again

mloskot:~/dev/gdal/bugs/641$ make

• Create empty.shp

mloskot:~/dev/gdal/bugs/641$ ./test

mloskot:~/dev/gdal/bugs/641$ ls
empty.dbf  empty.prj  empty.shp  empty.shx  Makefile  test  test2  test2.cpp  test.cpp

• Check empty.shp

mloskot:~/dev/gdal/bugs/641$ ogrinfo -ro empty.shp empty
OGR: OGROpen(empty.shp/0x804e550) succeeded as ESRI Shapefile.
INFO: Open of `empty.shp'
      using driver `ESRI Shapefile' successful.
OGR: GetLayerCount() = 1


Layer name: empty
Geometry: Point
Feature Count: 0
Extent: (0.000000, 0.000000) - (0.000000, 0.000000)
Layer SRS WKT:
(unknown)
dummy: Real (1.1)

• Open empty.shp again and add sample feature

mloskot:~/dev/gdal/bugs/641$ ./test2 
OGR: OGROpen(empty.shp/0x804d760) succeeded as ESRI Shapefile.

mloskot:~/dev/gdal/bugs/641$ ogrinfo -ro empty.shp empty
OGR: OGROpen(empty.shp/0x804e550) succeeded as ESRI Shapefile.
INFO: Open of `empty.shp'
      using driver `ESRI Shapefile' successful.
OGR: GetLayerCount() = 1


Layer name: empty
Geometry: Point
Feature Count: 1
Extent: (1.250000, 2.350000) - (1.250000, 2.350000)
Layer SRS WKT:
(unknown)
dummy: Real (1.1)
OGRFeature(empty):0
  dummy (Real) = 3.0
  POINT (1.25 2.35)

Shape: 1 features read on layer 

I think everything works here very well.

[Mateusz Łoskot]

As I checked above, everything works well: a) create empty shapefile and close it b) reopen and add features.

Marco, please, if you could confirm my analysis is OK and everything works for you too, I'd be thankful.

I'm closing this ticket as fixed.