QGIS » QGIS Application

I could not replicate the issue here (ubuntu, QGIS 2.14.1, manually set LANG=fr_FR.UTF-8). Seems to be an other setting that is off.

I have also :

LANGUAGE=fr_FR

As I can understand :

QGIS call gdal, and gdal call json-c.

In json-c, json is parse throuth :

struct json_object* json_tokener_parse_ex(struct json_tokener *tok,
                      const char *str, int len)
{
  // ... Short init code

#ifdef HAVE_SETLOCALE
  char *oldlocale=NULL, *tmplocale;

  tmplocale = setlocale(LC_NUMERIC, NULL);
  if (tmplocale) oldlocale = strdup(tmplocale);
  setlocale(LC_NUMERIC, "C");
#endif

  // ... Large main parser code is here

#ifdef HAVE_SETLOCALE
  setlocale(LC_NUMERIC, oldlocale);
  if (oldlocale) free(oldlocale);
#endif

  // ... Short error code
}

json-c use sscanf to convert string to int which is local sensitive.

int json_parse_double(const char *buf, double *retval)
{
  return (sscanf(buf, "%lf", retval)==1 ? 0 : 1);
}

Can there be interference with QGIS QgsLocaleNumC ?
(Used in QgsOgrProvider::addFeature and QgsOgrProvider::changeAttributeValues)

I don't think so (need QGIS to change locale in another thread, and ALL coordinates are truncated to int)

I think I found the problem. QGIS does not seem involved, but gdal and ubuntu.

First, even if ubuntu build of gdal require json-c, it seems to use gdal internal source.
In build log: https://launchpadlibrarian.net/220452462/buildlog_ubuntu-wily-amd64.gdal_1.11.2+dfsg-3ubuntu3_BUILDING.txt.gz (when configure of gdal) :

checking for json_object_set_serializer in -ljson-c... no
using internal libjson-c code

According to ldd :

$ ldd /usr/lib/libgdal.so | grep json
    libjson-c.so.2 => /lib/x86_64-linux-gnu/libjson-c.so.2 (0x00007f899fc82000)

But according to readelf, libjson isn't used :

$ readelf -d /usr/lib/libgdal.so | grep NEEDED
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libarmadillo.so.5]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libproj.so.9]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libpoppler.so.52]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libfreexl.so.1]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libgeos_c.so.1]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libwebp.so.5]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libepsilon.so.1]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libodbc.so.2]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libodbcinst.so.2]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libkmlbase.so.1]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libkmldom.so.1]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libkmlengine.so.1]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libexpat.so.1]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libxerces-c-3.1.so]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libopenjp2.so.7]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libjasper.so.1]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libnetcdf.so.7]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libhdf5_serial.so.10]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libmfhdfalt.so.0]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libdfalt.so.0]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libogdi.so.3.2]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libgif.so.4]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libjpeg.so.8]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libpng12.so.0]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libpq.so.5]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [liblzma.so.5]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libdapclient.so.6]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libdap.so.17]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libspatialite.so.7]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libpcre.so.3]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libcurl-gnutls.so.4]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libxml2.so.2]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libmysqlclient.so.18]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libpthread.so.0]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libz.so.1]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libdl.so.2]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libstdc++.so.6]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libm.so.6]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libc.so.6]
 0x0000000000000001 (NEEDED)             Bibliothèque partagée: [libgcc_s.so.1]

Secondly, gdal don't configure locale properly and don't set HAVE_SETLOCALE. Without this, in json-c internal code, the change of locale before call to sscanf is skip.

• gdal: https://trac.osgeo.org/gdal/ticket/6438
• ubuntu: https://bugs.launchpad.net/ubuntu/+source/gdal/+bug/1565475