[asterisk-bugs] [JIRA] (ASTERISK-25587) Libedit2 colored prompt is broken beyond repair

Rusty Newton (JIRA) noreply at issues.asterisk.org
Mon Nov 23 16:38:32 CST 2015


     [ https://issues.asterisk.org/jira/browse/ASTERISK-25587?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Rusty Newton updated ASTERISK-25587:
------------------------------------

    Component/s: Core/General

> Libedit2 colored prompt is broken beyond repair
> -----------------------------------------------
>
>                 Key: ASTERISK-25587
>                 URL: https://issues.asterisk.org/jira/browse/ASTERISK-25587
>             Project: Asterisk
>          Issue Type: Bug
>      Security Level: None
>          Components: Core/General
>    Affects Versions: 11.20.0, 13.6.0
>            Reporter: Walter Doekes
>            Severity: Minor
>
> Readline/bash uses {{\\\[}} and {{\\\]}} to delimit portions of the shell prompt that denote color (and do not move the cursor).
> For example:
> {noformat}
> PS1="`printf '\\[\033[32;1m\\]Prompt\\[\033[0m\\]$ '`"
> {noformat}
> Yields a colored prompt with "Prompt" in green.
> {noformat}
> Prompt$
> {noformat}
> The colorization bits aren't counted, and when you browse through history or move back from the next line, the prompt stays where it should be.
> If you omit the {{\\\[}} and the {{\\\]}}, the prompt behaves oddly when browsing the history or moving back from the next line:
> {noformat}
> PS1="`printf '\033[32;1mPrompt\033[0m$ '`"
> {noformat}
> Now, after arrow-up, arrow-down, the prompt looks like this:
> {noformat}
> Prompt$ PS1="`print<--- start of the prompt
> {noformat}
> Asterisk also allows one to colorize the prompt, but there is no working escape to not count the colorization bits:
> {noformat}
> ASTERISK_PROMPT='%C32Prompt%C5$ ' ./main/asterisk -c
> {noformat}
> That works, and gets you a green prompt. But it suffers from the readline problem as mentioned above (when you omit the {{\\\[}} and {{\\\]}}).
> Libedit2 claims to have a solution to that, by surrounding the colorization bits with {\\\1}}, like this. (Define color_start and color_end as {{"\\\1"}}.)
> {noformat}
> @@ -2625,10 +2633,16 @@ static char *cli_prompt(EditLine *editline)
>                                 case 'C': /* color */
>                                         t++;
>                                         if (sscanf(t, "%30d;%30d%n", &fgcolor, &bgcolor, &i) == 2) {
> -                                               ast_str_append(&prompt, 0, "%s", term_color_code(term_code, fgcolor, bgc
> +                                               ast_str_append(&prompt, 0, "%s%s%s",
> +                                                       color_start,
> +                                                       term_color_code(term_code, fgcolor, bgcolor, sizeof(term_code)),
> +                                                       color_end);
>                                                 t += i - 1;
>                                         } else if (sscanf(t, "%30d%n", &fgcolor, &i) == 1) {
> -                                               ast_str_append(&prompt, 0, "%s", term_color_code(term_code, fgcolor, 0, 
> +                                               ast_str_append(&prompt, 0, "%s%s%s",
> +                                                       color_start,
> +                                                       term_color_code(term_code, fgcolor, 0, sizeof(term_code)),
> +                                                       color_end);
>                                                 t += i - 1;
>                                         }
>  
> {noformat}
> and this:
> {noformat}
> @@ -2979,7 +3001,11 @@ static int ast_el_initialize(void)
>                 history_end(el_hist);
>  
>         el = el_init("asterisk", stdin, stdout, stderr);
> +#ifdef EL_PROMPT_ESC
> +       el_set(el, EL_PROMPT_ESC, cli_prompt, '\1');
> +#else
>         el_set(el, EL_PROMPT, cli_prompt);
> +#endif
>  
>         el_set(el, EL_EDITMODE, 1);
>         el_set(el, EL_EDITOR, editor);
> {noformat}
> However, the above only works if you define *only* one color and no color reset because of this bug:
> http://gnats.netbsd.org/47539
> _The color sequence is output out of band of the non-color, so all the colors strings (both the set and the reset) end up before the the prompt is printed: the prompt gets no color. (This was confirmed with the libedit-3.1-20130712 version from Ubuntu Trusty.)_
> This is not easily fixable within libedit2 because of how the virtual buffer works. (Perhaps it's fixed somewhere, I didn't find it easily.)
> To make matters worse, the color reset in Asterisk is also broken:
> {noformat}
>                 if (color_used) {
>                         /* Force colors back to normal at end */
>                         ast_str_append(&prompt, 0, "%s", term_color_code(term_code, 0, 0, sizeof(term_code)));
>                 }
> {noformat}
> That bit does not work, because fgcolor is 0, and when it is 0, we end up here. (Read as: the patch fixes that problem.)
> {noformat}
> @@ -265,7 +265,7 @@ char *term_color_code(char *outbuf, int fgcolor, int bgcolor, int maxout)
>  {
>         int attr = 0;
>  
> -       if (!check_colors_allowed(fgcolor)) {
> +       if (!check_colors_allowed()) {
>                 *outbuf = '\0';
>                 return outbuf;
>         }
> ...
> @@ -234,16 +234,16 @@ static void check_bgcolor(int *bgcolor)
>         }
>  }
>  
> -static int check_colors_allowed(int fgcolor)
> +static int check_colors_allowed(void)
>  {
> -       return (!vt100compat || !fgcolor) ? 0 : 1;
> +       return vt100compat;
>  }
>  
> {noformat}
> On top of all the above, the colored prompt has been broken in rasterisk (-r) for quite some time -- I believe, see ASTERISK-25585. So if we dropped support for it, no one would notice.
> Suggested fix: *drop color support*
> Something like this:
> {noformat}
> --- a/main/asterisk.c
> +++ b/main/asterisk.c
> @@ -2625,10 +2625,8 @@ static char *cli_prompt(EditLine *editline)
>                                 case 'C': /* color */
>                                         t++;
>                                         if (sscanf(t, "%30d;%30d%n", &fgcolor, &bgcolor, &i) == 2) {
> -                                               ast_str_append(&prompt, 0, "%s", term_color_code(term_code, fgcolor, bgc
>                                                 t += i - 1;
>                                         } else if (sscanf(t, "%30d%n", &fgcolor, &i) == 1) {
> -                                               ast_str_append(&prompt, 0, "%s", term_color_code(term_code, fgcolor, 0, 
>                                                 t += i - 1;
>                                         }
>  
> {noformat}
> (Sorry for the inline patch, I hereby release all my copyright claims, like usual.)
> (Argh, JIRA refuses to give a literal BASKSLASH-BRACKET. Only three backslashes work, but when it displays all three... Gah.)



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