Re: Prompt overwrites command output if prompt contains unicode character and non-printing escape sequence

Dear Chet,

Do you mean that commands should output a newline at the end? I don't 
have control over what all commands do that I run, and sometimes they 
don't end with a newline. It would be nice if I could still read their 
last lines, like in bash 5.2.

In bash 5.3 it also works fine for prompts without unicode characters, 
for example:

bash-5.3$ echo -n test
testbash-5.3$

On bash 5.2 this also works fine:

bash-5.2$ PS1='€ \[\e[0m\]'
€ echo -n test
test€

Best,

Lennart


On 5/18/26 6:07 PM, Chet Ramey wrote:
> On 5/16/26 3:28 PM, Lennart Ackermans via Bug reports for the GNU 
> Bourne Again SHell wrote:
>
>> Bash Version: 5.3
>> Patch Level: 9
>> Release Status: release
>>
>> Description:
>>      If $PS1 contains a unicode character followed by an escape 
>> sequence, the prompt appears to be output twice if a command ends 
>> without a newline: once (correctly) after the output and once at the 
>> beginning of the line, overwriting the output. The cursor is placed 
>> after the first, overwriting prompt (on "s" in the example below).
>>
>>    This bug was not present in Bash 5.2.
>>
>> Repeat-By:
>>      bash-5.3$ PS1='€ \[\e[0m\]'
>>      € echo -n test
>>      € st€
>
> If the cursor isn't at position 0 when readline starts, results will be
> unpredictable. Readline has to know where it is on the screen so it can
> make decisions about which escape sequences to use to move the cursor.
> This isn't necessarily the result of having any particular characters in
> the prompt string, though having a sequence of non-printing characters
> means that readline really does need to know where it is on the screen.
>
> A simple newline will fix this.
>