Hello,

I have just migrated from a 32bit system to a new 64bit system, running Kubuntu Natty and Qt 4.7.2. I have recompiled an application that used to work perfectly on the 32bit system and now I am getting a crash while inserting rows into a Postgresql database.

The following is the code, it just reads a CSV file line by line and inserts each line into a Postgresql table. The database connection has been opened successfully at a different place in the application. The crash occurs at query.exec() inside the while() loop on line 51:

Qt Code: 
  1. void TickerImportThread::run()
  2. {
  3.     status = true;
  4.  
  5.     QSqlQuery query;
  6.     QFile file(filename);
  7.  
  8.     if ( !file.open(QIODevice::Text | QIODevice::ReadOnly) )
  9.     {
  10.         status = false;
  11.         return;
  12.     }
  13.  
  14.     QSqlDatabase::database().transaction();
  15.  
  16.     if ( !query.exec("DELETE FROM \"bardata_M1\"") )
  17.     {
  18.         status = false;
  19.         QSqlError error = query.lastError();
  20.         qDebug() << Q_FUNC_INFO << "SQL Error: " << error.databaseText() << error.driverText();
  21.         QSqlDatabase::database().rollback();
  22.         return;
  23.     }
  24.  
  25.     QByteArray line;
  26.     QList<QByteArray> items;
  27.     long filesize = file.size();
  28.     long completed = 0;
  29.     int percentage = 0;
  30.  
  31.     if ( !query.prepare("INSERT INTO \"bardata_M1\" (symbol, \"time\", open, high, low, \"close\") VALUES ('EURUSD', :v_time, :v_open, :v_high, :v_low, :v_close)") )
  32.     {
  33.         status = false;
  34.         QSqlError error = query.lastError();
  35.         qDebug() << Q_FUNC_INFO << "SQL Error: " << error.databaseText() << error.driverText();
  36.         QSqlDatabase::database().rollback();
  37.         return;
  38.     }
  39.  
  40.     while ( !file.atEnd() )
  41.     {
  42.         line = file.readLine();
  43.         items = line.split(',');
  44.  
  45.         query.bindValue(":v_time", QString(items[0]) + " " + QString(items[1]));
  46.         query.bindValue(":v_open", items[2]);
  47.         query.bindValue(":v_high", items[3]);
  48.         query.bindValue(":v_low", items[4]);
  49.         query.bindValue(":v_close", items[5]);
  50.  
  51.         if ( !query.exec() )
  52.         {
  53.             status = false;
  54.             QSqlError error = query.lastError();
  55.             qDebug() << Q_FUNC_INFO << "SQL Error: " << error.databaseText() << error.driverText();
  56.             QSqlDatabase::database().rollback();
  57.             return;
  58.         }
  59.  
  60.         completed += line.length();
  61.         double newpercentage = (double)completed / (double)filesize * 100;
  62.         if ( round(newpercentage) > percentage )
  63.         {
  64.             percentage = round(newpercentage);
  65.             emit importProgress(percentage);
  66.         }
  67.     }
  68.  
  69.     emit importProgress(100);
  70.  
  71.     QSqlDatabase::database().commit();
  72.  
  73.     file.close();
  74. }
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This is the backtrace:

Qt Code: 
  1. *** glibc detected *** /home/till/forex-build-desktop/forex: double free or corruption (fasttop): 0x000000000094aa70 ***
  2. ======= Backtrace: =========
  3. /lib/x86_64-linux-gnu/libc.so.6(+0x78a8f)[0x7ffff5370a8f]
  4. /lib/x86_64-linux-gnu/libc.so.6(cfree+0x73)[0x7ffff53748e3]
  5. /lib/libcrypto.so.0.9.8(CRYPTO_free+0x1d)[0x7fffeb6b0efd]
  6. /lib/libssl.so.0.9.8(SSL_free+0x49)[0x7fffeba0e199]
  7. /usr/lib/libpq.so.5(+0x19e8d)[0x7fffebc45e8d]
  8. /usr/lib/libpq.so.5(+0x11bc9)[0x7fffebc3dbc9]
  9. /usr/lib/libpq.so.5(PQgetResult+0x9d)[0x7fffebc3bbcd]
  10. /usr/lib/libpq.so.5(+0xfe6b)[0x7fffebc3be6b]
  11. /usr/lib/qt4/plugins/sqldrivers/libqsqlpsql.so(+0xe327)[0x7fffebe62327]
  12. /usr/lib/libQtSql.so.4(_ZN9QSqlQuery4execEv+0xc5)[0x7ffff718cf15]
  13. /home/till/forex-build-desktop/forex[0x40fc0e]
  14. /usr/lib/libQtCore.so.4(+0x74175)[0x7ffff60bf175]
  15. /lib/x86_64-linux-gnu/libpthread.so.0(+0x6d8c)[0x7ffff5e33d8c]
  16. /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7ffff53de04d]
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I'm not sure how to debug this, my guess is that it is libssl's fault, but I could not find anything related on the web. Is there any problem in my code? If not, any tips for debugging or even fixing this?