> "fix-readline-related-bug.patch" does that. Bloody parentheses. This is better.
Cheers.
Description: Fix readline-related bug Non-printable character (meant to be interpreted by the terminal) in the prompt string was not enclosed in RL_PROMPT_START_IGNORE/RL_PROMPT_END_IGNORE pairs, resulting in improper behaviour by GNU readline. . This is a Scheme-only fix, but it's not ideal because it hardcodes libreadline constants. Ideally, "Iedline.scm" would get eval-ed in an environment where C code has made the constants (from <readline/readline.h>) available. This way the constants are not hardcoded in the source code and the Scheme namespace is not polluted with implementation details. Author: astian <ast...@elude.in> Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=831017 Forwarded: no Last-Update: 2018-03-05 --- scm-5f2.orig/Iedline.scm +++ scm-5f2/Iedline.scm @@ -23,7 +23,17 @@ ;; lines, i.e. lines unterminated by a newline. (define (make-edited-line-port) - (let ((prompt "") + (let ; The prompt string we receive. + ((prompt "") + ; Hack to make readline overwrite the prompt we manually write. + ; Notice that #\cr is being wrapped in #\soh and #\stx, respectively + ; RL_PROMPT_START_IGNORE and RL_PROMPT_END_IGNORE (defined in + ; <readline/readline.h>), to signal to readline that #\cr is + ; invisible. + (prompt-hack (string #\soh #\cr #\stx)) + ; Concatenation of "prompt-hack" and "prompt", this is the actual + ; prompt we send to readline. + (prompt-real "") (outp (default-output-port)) (inp (default-input-port)) (strp (call-with-input-string "" identity))) @@ -31,18 +41,40 @@ (vector (lambda (c) (write-char c outp)) (lambda (s) + ; Reverse-engineered assumption: string-write to this port will + ; only be done in the following cases: + ; + ; - Empty string. + ; + ; - Printing repl results, in which case the string will + ; always come linefeed-terminated. + ; + ; - Prompt printing, which will never be linefeed-terminated. + ; The prompt string is immediately printed (manually), + ; later, when GNU readline is called, a carriage return + ; prepended to the same prompt string will cause it to + ; write its prompt on top of the one we printed ourselves + ; (therefore only one instance of the prompt string is + ; actually visible to the interactive user). Presumably + ; this is the result of kluging optional readline support + ; on top of an existing prompting mechanism. + ; + ; -- astian (display s outp) (or (zero? (string-length s)) (eq? #\newline (string-ref s (- (string-length s) 1))) (begin - (set! prompt (string-append "\r" s)) + (or (string=? s prompt) + (begin + (set! prompt s) + (set! prompt-real (string-append prompt-hack prompt)))) (force-output outp)))) (lambda () (force-output outp)) (lambda () (let tail ((c (read-char strp))) (if (char? c) c - (let ((str (read-edited-line prompt))) + (let ((str (read-edited-line prompt-real))) (if (string? str) (let ((n (string-length str))) (add-history str)
