[PATCH v2] prompt: support generic non-visible regions

[Felipe Contreras <felipe.contreras@xxxxxxxxx>]

readline uses \001 (start of header) and \002 (start of text) as markers
to delimit a non-visible character zone, which are necessary to
calculate the width of a prompt.

In zsh we do this with %{ and %}, but we could support
\001 and \002 as well, so that a function which generates output for
the prompt can use colors in a way that works for both bash and zsh.

This additionally has the benefit of allowing prompts without
PROMPT_PERCENT to use colors correctly.

Signed-off-by: Felipe Contreras <felipe.contreras@xxxxxxxxx>
---

No changes since v1 other than the commit message.

 Src/prompt.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Src/prompt.c b/Src/prompt.c
index 092de63a4..803937029 100644
--- a/Src/prompt.c
+++ b/Src/prompt.c
@@ -886,6 +886,12 @@ putpromptchar(int doprint, int endchar, zattr *txtchangep)
 		    bv->bp += strlen(bv->bp);
 		}
 	    }
+	} else if(*bv->fm == 0x01) { // start non-visible characters
+	    addbufspc(1);
+	    *bv->bp++ = Inpar;
+	} else if(*bv->fm == 0x02) { // end non-visible characters
+	    addbufspc(1);
+	    *bv->bp++ = Outpar;
 	} else {
 	    char c = *bv->fm == Meta ? *++bv->fm ^ 32 : *bv->fm;
 
-- 
2.37.1