Shift: Infinite recursion in midi-components-0.0.js

[mixxxbot]

Reported by: uklotzde
Date: 2020-05-27T22:01:49Z
Status: Fix Released
Importance: High
Launchpad Issue: lp1881027
Tags: controllers

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In 2.3 my MC6000MK2 is almost unusable. Pressing shift triggers an infinite recursion. 2 message boxes appear in short succession:

1st message box:
Uncaught exception at line 524 in file /tmp/mixxx/res/controllers/midi-components-0.0.js.

Exception:
RangeError: Maximum call stack size exceeded.

Backtrace:

2nd message box:
Uncaught exception at line 139 in file /tmp/mixxx/res/controllers/midi-components-0.0.js.

Exception:
RangeError: Maximum call stack size exceeded.

Backtrace:

Running Mixxx with --controllerDebug shows this output:
Debug [Controller]: MC6000MK2 MIDI 1: t:26054 ms status 0x90 (ch 1, opcode 0x9), ctrl 0x60, val 0x40
Warning [Controller]: ControllerEngine: "Uncaught exception at line 524 in file /tmp/mixxx/res/controllers/midi-components-0.0.js.\n\nException:\n  RangeError: Maximum call stack size exceeded.\n\nBacktrace:\n  "
Debug [Controller]: MidiController: Invalid script function "DenonMC6000MK2.leftDeck1.shiftButtonInput"
Debug [Controller]: MC6000MK2 MIDI 1: t:26162 ms status 0x80 (ch 1, opcode 0x8), ctrl 0x60, val 0x00
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1], focused_effect) from connection {6286ce20-a3c9-44be-8733-0a0ad2332962}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1_Effect1], enabled) from connection {a8f7bafe-06bf-416a-a650-11122329bad1}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1], focused_effect) to connection {75282d04-5040-48cc-b6a4-afb14be2a442}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1_Effect1], enabled) to connection {3d4e8f31-6aa9-4a75-b5fb-a1ba2e636d1b}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1], focused_effect) from connection {ceff76fb-8ea0-4dce-99ec-6dff50bc5a94}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1_Effect2], enabled) from connection {0b1ef646-937d-4d6d-92ac-793556ec5452}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1], focused_effect) to connection {5c20df21-7ab7-4106-a826-c033033df903}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1_Effect2], enabled) to connection {86a18f7c-0a25-4ade-b513-3b3f38da5127}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1], focused_effect) from connection {fc040c93-7ffa-4771-b719-366f7910a13f}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1_Effect3], enabled) from connection {6bed9f55-5306-473c-b40c-9b1e64588320}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1], focused_effect) to connection {85f6d70b-2dc1-4025-b456-789f192e1e61}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1_Effect3], enabled) to connection {4eda1b12-ccf3-44b6-82d4-aa2d4c82690e}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1], focused_effect) from connection {75282d04-5040-48cc-b6a4-afb14be2a442}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1_Effect1], enabled) from connection {3d4e8f31-6aa9-4a75-b5fb-a1ba2e636d1b}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1], focused_effect) to connection {e053bf0a-3531-4d5e-8df5-d3c307c09bb9}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1_Effect1], enabled) to connection {ecf55e5d-804e-4dbb-b126-78f163efc012}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1], focused_effect) from connection {5c20df21-7ab7-4106-a826-c033033df903}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1_Effect2], enabled) from connection {86a18f7c-0a25-4ade-b513-3b3f38da5127}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1], focused_effect) to connection {284ec40f-9a55-42ed-81a7-47ddf35de477}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1_Effect2], enabled) to connection {2d15f340-279b-483e-9127-4b26f91661ad}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1], focused_effect) from connection {85f6d70b-2dc1-4025-b456-789f192e1e61}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1_Effect3], enabled) from connection {4eda1b12-ccf3-44b6-82d4-aa2d4c82690e}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1], focused_effect) to connection {b74c9db4-1017-472d-8c75-b210c73c50ac}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1_Effect3], enabled) to connection {c321db7f-3aab-4053-9212-1636d6699769}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1], focused_effect) from connection {e053bf0a-3531-4d5e-8df5-d3c307c09bb9}
Debug [Controller]: Disconnected ([EffectRack1_EffectUnit1_Effect1], enabled) from connection {ecf55e5d-804e-4dbb-b126-78f163efc012}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1], focused_effect) to connection {b310b362-baf8-4243-9de2-1d99f3f9db86}
Debug [Controller]: Connected ([EffectRack1_EffectUnit1_Effect1], enabled) to connection {3812dea1-ecc2-4dce-ad56-0fea3c6d49e5}
...

I have no idea where to start the analysis? 2.2 works flawlessly.

[mixxxbot]

Commented by: Be-ing
Date: 2020-05-27T22:13:35Z

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My first guesses would be a regression introduced by #2588 or #2569

I have no idea where to start the analysis?

A perfect case for Git bisect :)

[mixxxbot]

Commented by: uklotzde
Date: 2020-05-27T23:05:17Z

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I guess it could be the introduction of forEachComponentContainer

[mixxxbot]

Commented by: uklotzde
Date: 2020-05-27T23:10:13Z

---

#2266

[mixxxbot]

Commented by: uklotzde
Date: 2020-05-29T21:12:29Z

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Storing a reference to a parent ComponentContainer causes an infinite loop in the recursive shift/unshift handling. The implicit recursion is convenient but dangerous.

Workaround: Don't store references to parent ComponentContainer as a member.

Workaround for Denon MC6000MK2: #2833

[mixxxbot]

Issue closed with status Fix Released.