From bf810e9c50050c597576044e2b930915b0bb2811 Mon Sep 17 00:00:00 2001
From: Alessandro Pasotti <elpaso@itopen.it>
Date: Sat, 9 Jun 2018 18:42:14 +0200
Subject: [PATCH] Check if conversion was successful before passing to locale

---
 src/core/qgsfield.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/core/qgsfield.cpp b/src/core/qgsfield.cpp
index 09890895056..0b056b1aa82 100644
--- a/src/core/qgsfield.cpp
+++ b/src/core/qgsfield.cpp
@@ -244,11 +244,14 @@ QString QgsField::displayString( const QVariant &v ) const
       return QString::number( v.toDouble(), 'f', d->precision );
     }
   }
-  // Other numeric types out of doubles
+  // Other numeric types than doubles
   else if ( isNumeric() &&
             ! QLocale().numberOptions() & QLocale::NumberOption::OmitGroupSeparator )
   {
-    return QLocale().toString( v.toLongLong() );
+    bool ok;
+    qlonglong converted( v.toLongLong( &ok ) );
+    if ( ok )
+      return QLocale().toString( converted );
   }
   // Fallback if special rules do not apply
   return v.toString();
@@ -305,7 +308,7 @@ bool QgsField::convertCompatible( QVariant &v ) const
     QVariant tmp( v );
     if ( d->type == QVariant::Double && !tmp.convert( d->type ) )
     {
-      v = v.toString().replace( ',', '.' );
+      v = v.toString().replace( QLocale().decimalPoint(), '.' );
     }
   }