[fdo-trac] #732: WFS: segv on Linux when read feature with many coordinates

[FDO]

#732: WFS: segv on Linux when read feature with many coordinates
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 Reporter:  brentrobinson               |         Owner:  brentrobinson
     Type:  defect                      |        Status:  closed       
 Priority:  major                       |     Milestone:  3.6.0        
Component:  FDO API                     |       Version:  3.5.0        
 Severity:  2                           |    Resolution:  fixed        
 Keywords:  WFS segv linux coordiantes  |   External_id:               
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Changes (by brentrobinson):

  * status:  new => closed
  * resolution:  => fixed


Comment:

 Revision: 5837
 Author: brentrobinson
 Date: 8:02:35 AM, Tuesday, November 30, 2010
 Message:
 Ticket#739: Fixed a stack overflow which happens when reading features
 from XML on Linux. It occurs when a feature has a huge number of
 coordinates (about 97,000).

 FdoXmlCoordinateGroup parses a wide-char coordinate string. On Linux, it
 converts each ordinate to multibyte before converting to double. Space for
 the intermediate multbyte was allocated on the program stack (using
 alloca). Items allocated by alloca are freed when the current function
 returns. However, the ordinates were processed in a loop, meaning that the
 stack could overflow if there were enough ordinates.

 The fix was to add a function to convert each ordinate. This ensures that
 each intermediate multibyte string is free before the next one is
 allocated.

 Some other fixes were also done to facilitate writing a unit test to cover
 this case:

 FdoXmlFeatureReaderImpl: changed GetClassDefinition() to return the class
 definition for the current feature if it can be determined. This allows
 the FdoXmlFeatureSerializer to round trip from an FdoXmlFeatureReader to
 an FdoXmlFeatureWriter.

 FdoXmlFeaturePropertyReaderImpl: send the current feature's class
 definition via the FeatureStart event, if the class definition can be
 determined.

 FdoXmlSchemaManager: if XML Schema mappings not set on the XML Flags that
 were passed in, check if they can be retrieved from the feature schemas.
 This provides a bit more convenience. If the app deserializes the feature
 schemas and passes them to an FdoXmlFeatureReader, the app no longer has
 to transfer the XML schema mappings from the feature schemas to the flags.
 ----
 Modified : /trunk/Fdo/UnitTest/CMakeLists.txt
 Modified : /trunk/Fdo/UnitTest/GmlTest.cpp
 Modified : /trunk/Fdo/UnitTest/GmlTest.h
 Modified : /trunk/Fdo/UnitTest/Makefile.am
 Added : /trunk/Fdo/UnitTest/hawaii_in.xml
 Added : /trunk/Fdo/UnitTest/hawaii_schema.xml
 Modified : /trunk/Fdo/Unmanaged/Src/Fdo/Xml/CoordinateGroup.cpp
 Modified : /trunk/Fdo/Unmanaged/Src/Fdo/Xml/FeaturePropertyReaderImpl.cpp
 Modified : /trunk/Fdo/Unmanaged/Src/Fdo/Xml/FeatureReaderImpl.cpp
 Modified : /trunk/Fdo/Unmanaged/Src/Fdo/Xml/FeatureReaderImpl.h
 Modified : /trunk/Fdo/Unmanaged/Src/Fdo/Xml/SchemaManager.cpp

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Ticket URL: <http://trac.osgeo.org/fdo/ticket/732#comment:1>
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