Do not crash if the child index is out of range.

Task-number: QTBUG-29077

Change-Id: I934101cdc121e9ef99de2e9eeaef154dd4cae0d8
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>
Check if the interface pointer is valid to avoid a potential crash.

Change-Id: I7e6634b799e551786d6cbc85e2d526b7874ada3d
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>
Fix lupdate-warning in qnetworkreplyhttpimpl.cpp.

qnetworkreplyhttpimpl.cpp:666: Cannot invoke tr() like this.

Change-Id: I3baf448f2118b108c32dcddc7e408b2b75542eab
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Spell "Qt" correctly

Change-Id: Idf2b5c888f159ee8ffdb81ed74e685c40951c6b4
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>