Missing history length check in ScreenTerminal

[Elec332]

The setSize() function in ScreenTerminal https://github.com/jline/jline3/blob/master/builtins/src/main/java/org/jline/builtins/ScreenTerminal.java#L1614 resizes the screen as required.
When the screen height gets increased after being decreased, the function will "reinstate" a few history lines.

Where all the original line are increased in length to be (at least) the proper width with Arrays.copyOf() (https://github.com/jline/jline3/blob/master/builtins/src/main/java/org/jline/builtins/ScreenTerminal.java#L1622), the length of the historic lines is never checked: https://github.com/jline/jline3/blob/master/builtins/src/main/java/org/jline/builtins/ScreenTerminal.java#L1660

As a sizenote:
When the array in increased in size with Array.copyOf(), the rest of the array is initialized with 0's, instead of attr | 0x00000020 (space), so there will be width issues when rendering them as AttributedStrings, as a null char has no width

[gnodet]

I've submitted a fix for this issue in PR #1207.

The problem was that when history lines are pulled back into the screen during a resize operation, their width was never checked or adjusted to match the new terminal width. This could cause rendering issues with null characters.

The fix adds a width check for history lines in the ScreenTerminal.setSize() method and properly resizes them if needed, filling the new space with spaces. A unit test has been added to verify the fix.

[gnodet]

@Elec332 could you please double check that the PR fixes the problem you saw ?

[Elec332]

Looks good, it would however be nice if the space-insertion check would also be done on resized parts without history
https://github.com/gnodet/jline3/blob/d63b3efce6c730c15554a0a71997fb974de4bffb/builtins/src/main/java/org/jline/builtins/ScreenTerminal.java#L1620

As now it's just inserting 0's (as described above)