vcl: use DeviceCoordinate for GetCaretPositions in sallayout

Change-Id: I5a959e1c3806da713e106c1b0fc8690a6578987b
coverity#735600 Division by zero

Change-Id: Ia936814ae37ae802fab36f7bde56de09338eb617
coverity#703951 unchecked return value

Change-Id: Id9a3c639bd778552b176c19b7574a9d9786ffebc
fix access to potentiellement empty string

Change-Id: I84fc6b7e5528b677411163ee3c9d05d4f2e6feb2
bug wrong order of test cause out of bound access.

Change-Id: If9c497473bc163677175b0fda1f3a8975cceb3dd
ucb: prevent out of bound access in OUString

Change-Id: I451bf13cbf39ec13152d083a6a6728cd043f9fbd
xmlscript: avoid accessing [0] of an emptry string

Change-Id: I2ad756b07418d3eb93f48374cd7de3bc3db9ce29
svl: test lenght before access

Change-Id: Ia0f41da43f150cd664dd9d4b5adef4e387253bf8
harden access to OUString[0]

Change-Id: Ibc2997f9974b8f6d561db0632642060ab95b80f0
vcl: protect against out-of-bound access of empty OUString

Change-Id: If2671ba0547eb69fce7005f5427dcd175a5c29a2