Python console history gets rearranged when editing lines #46809

New Issue

Mikko Rasa · 2015-11-18T11:47:06+01:00

Mikko Rasa commented

2015-11-18 11:47:06 +01:00

System Information
Debian unstable, GeForce GTX 980

Blender Version
Broken: 2.76

Short description of error
Editing lines in the Python console causes the console's history order to be manipulated in unintuitive ways. There is a certain logic to it, but that logic is different from just about every other shell in existence(*). Most importantly, it's different from Python's own interactive interpreter.

(*) Based on a sample (n=4) consisting of bash, python3, cmd.exe and Opera's Javascript console

Exact steps for others to reproduce the error
Because Python console contents are not saved, I think it's pointless to attach a .blend file.

Open Python console in Blender
Seed the history with the integers 1, 2 and 3 in this order
Press up arrow two times to get back to 2
Edit the value to 42 and press enter
Press up arrow repeatedly and observe the history cycling order
The history order is now 42 -> 2 -> 1 -> 3 -> back to empty line.
If you press the down arrow twice between steps 4 and 5 (it cycles to 3 and then empty line), the history order becomes 3 -> 42 -> 2 -> 1 -> back to empty line. One press of the down arrow is not enough to trigger this.

**System Information** Debian unstable, GeForce GTX 980 **Blender Version** Broken: 2.76 **Short description of error** Editing lines in the Python console causes the console's history order to be manipulated in unintuitive ways. There is a certain logic to it, but that logic is different from just about every other shell in existence(*). Most importantly, it's different from Python's own interactive interpreter. (*) Based on a sample (n=4) consisting of bash, python3, cmd.exe and Opera's Javascript console **Exact steps for others to reproduce the error** Because Python console contents are not saved, I think it's pointless to attach a .blend file. 1. Open Python console in Blender 2. Seed the history with the integers 1, 2 and 3 in this order 3. Press up arrow two times to get back to 2 4. Edit the value to 42 and press enter 5. Press up arrow repeatedly and observe the history cycling order The history order is now 42 -> 2 -> 1 -> 3 -> back to empty line. If you press the down arrow twice between steps 4 and 5 (it cycles to 3 and then empty line), the history order becomes 3 -> 42 -> 2 -> 1 -> back to empty line. One press of the down arrow is not enough to trigger this.

Mikko Rasa commented

2015-11-18 11:47:06 +01:00

Changed status to: 'Open'

Mikko Rasa commented

2015-11-18 11:47:06 +01:00

Added subscriber: @tdb

Campbell Barton self-assigned this 2015-11-18 20:37:54 +01:00

Bastien Montagne commented

2015-11-19 15:50:39 +01:00

Added subscriber: @mont29

Campbell Barton removed their assignment 2016-08-03 06:34:49 +02:00

Campbell Barton commented

2016-08-03 06:34:49 +02:00

Added subscriber: @ideasman42

Germano Cavalcante commented

2020-01-22 14:47:49 +01:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2020-01-22 14:47:49 +01:00

I can confirm.
42 is added to the history after 2.
It should have been added to the end of the history list.

I can confirm. 42 is added to the history after 2. It should have been added to the end of the history list.

Bastien Montagne commented

2020-01-22 16:21:47 +01:00

This is not technically a bug, code is supposed to work that way… Has been a long-standing TODO to revisit this and get a more usual behavior of commandline history, so moving to known issue.

Chirag Mathur commented

2022-03-30 21:38:20 +02:00

Added subscriber: @Chirag-Mathur

Chirag Mathur commented

2022-03-31 09:58:00 +02:00

I have been able to reproduce this issue and would like to work on this, so can anyone point me as to where to start.
I think this is similar to what happens in the MySQL command line clients, where the anchor is placed to wherever we go via the arrow keys, and the changes we do, like the 42, are added there only instead of being added to the last of the history.

I have been able to reproduce this issue and would like to work on this, so can anyone point me as to where to start. I think this is similar to what happens in the MySQL command line clients, where the anchor is placed to wherever we go via the arrow keys, and the changes we do, like the 42, are added there only instead of being added to the last of the history.

Matheus Cavazotti commented

2022-04-06 20:27:02 +02:00

Added subscriber: @mcavazotti

Matheus Cavazotti commented

2022-04-06 20:27:02 +02:00

I'm working on this item.

From what I saw in the code, a circular linked list could simplify how the console history is implemented and could do the trick to fix this issue. However I couldn't find any circular linked list in the blender/source/blender/blenlib folder. Since I'm new in the dev community, I don't know if I can implement a CircularList based on ListBase or if I should look for another solution for this task... Can anyone give me an advice about it?

I'm working on this item. From what I saw in the code, a circular linked list could simplify how the console history is implemented and could do the trick to fix this issue. However I couldn't find any circular linked list in the `blender/source/blender/blenlib` folder. Since I'm new in the dev community, I don't know if I can implement a `CircularList` based on `ListBase` or if I should look for another solution for this task... Can anyone give me an advice about it?

Campbell Barton commented

2022-04-07 01:54:11 +02:00

I don't think a circular linked list is needed, it's not such a problem to wrap to the first/last when cycling history.

Matheus Cavazotti self-assigned this 2022-04-07 21:21:51 +02:00

Matheus Cavazotti commented

2022-04-07 21:21:51 +02:00

The fix is in this patch [D14592 ](https://developer.blender.org/D14592), ready for review.

The fix is in this patch [[D14592](https://archive.blender.org/developer/D14592) ](https://developer.blender.org/D14592), ready for review.

Matheus Cavazotti commented

2022-04-15 03:02:49 +02:00

@ideasman42 How do I ask for someone to review my patch? I couldn't find the details about it in the wiki...

Angus Stanton commented

2022-04-21 02:54:39 +02:00

Added subscriber: @ab_stanton

Angus Stanton commented

2022-04-21 02:54:39 +02:00

In #46809#1341424, @mcavazotti wrote:
@ideasman42 How do I ask for someone to review my patch? I couldn't find the details about it in the wiki...

Just tag them in the patch (click edit, then in reviewers type in the name of who you want to review it). If you're active in blender.chat you can always chase them up on there if you think it's getting lost, but these things take time so normally you'll have just have to wait for a good bit.

> In #46809#1341424, @mcavazotti wrote: > @ideasman42 How do I ask for someone to review my patch? I couldn't find the details about it in the wiki... Just tag them in the patch (click edit, then in reviewers type in the name of who you want to review it). If you're active in blender.chat you can always chase them up on there if you think it's getting lost, but these things take time so normally you'll have just have to wait for a good bit.

Philipp Oeser removed the

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Python console history gets rearranged when editing lines #46809