ASSERT: "samples_needed >= 0" in file src/engine/readaheadmanager.cpp when holding finger on MIDI controller during scratching

[mixxxbot]

Reported by: Pegasus-RPG
Date: 2010-06-02T14:06:50Z
Status: Fix Released
Importance: High
Launchpad Issue: lp588729
Tags: assert, crash, engine

---

Trunk r2407 introduced a bug that causes the following error when using a MIDI controller with the new scratch behavior and just holding my finger so the track is stopped. (Can be exaserbated by lower latency and toggling Play while holding the track.)

Fatal: []: ASSERT: "samples_needed >= 0" in file src/engine/readaheadmanager.cpp, line 61

This happens on Linux and Windows. Tested with an SCS.3d.

[mixxxbot]

Commented by: rryan
Date: 2010-06-04T21:02:37Z

---

Albert, Sean and I tracked this down to samples_needed going negative in EngineBufferScaleLinear. The logic to subtract the remainder was subtracting from samples_needed such that it went negative. In r2407, two asserts in EBSL that verify that samples_needed is greater than 0 were disabled, so the problem propagated to the RAMAN once EBSL tried to read with a negative samples_needed.

[mixxxbot]

Issue closed with status Fix Released.