MQ Coder encode: Conditional jump or move depends on uninitialised value(s)

[boxerab]

http://my.cdash.org/viewDynamicAnalysisFile.php?id=3409924

  if (*mqc->bp == 0xff) {
    mqc->bp++;
    *mqc->bp = (OPJ_BYTE)(mqc->c >> 20);
    mqc->c &= 0xfffff;
    mqc->ct = 7;
} else {

This is because mq->bp is initialized to one less than the actual data start address.
It could be possible for uninitialized memory to be equal to 0xFF, in which case there will be an error in the code stream. For lossless encoding, this could lead to lossy encoding.

An easy fix is to check if mqc->bp < mqc->start before entering the if statement.
On a modern CPU with branch prediction, there should be no performance hit.

[mayeut]

Is that the same than #612 ? Maybe also #539 ?

[boxerab]

yes, it looks like #612, #539 is different

[mayeut]

@boxerab closing this one as duplicate.

Follow-up in #612