Clone of MC-88858 that was incorrectly closed.
This issue is NOT a duplicate of MC-87605 as that issue relates to sign rendering (and is working as intended), and this issue is about sign creation.
---------------
Sign rendering has been limited in 1.8 based on the resource pack itself how it renders the text.That is fine and all, but it also impacts simply setting up the sign.

For example, a user with a custom resource pack using larger fonts can't write as many characters on a sign line than another resource pack can.

Truncating the message on sign viewing is accepted, but the client should not be as strict on sign creation, as a sign created on one resource pack may over flow but be perfectly visible on another.

Even more so, users using the vanilla resource pack are reporting being unable to write their character name on a sign due to this.
name: Merek_Shadowmere

Suggestion: Client should allow writing up to 32 characters, and then let viewing the sign enforce the rendering based calculations.

Then activities that read the sign data can at least see full name, even if client can not.