[Guile-commits] GNU Guile branch, stable-2.0, updated. v2.0.3-16-gdceb782

[Andy Wingo]

This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU Guile".

http://git.savannah.gnu.org/cgit/guile.git/commit/?id=dceb78294d381e6c3b9779b3f4a186cb76415054

The branch, stable-2.0 has been updated
       via  dceb78294d381e6c3b9779b3f4a186cb76415054 (commit)
      from  440ac793c4f32d1eeef89eb9974be39270c18069 (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------
commit dceb78294d381e6c3b9779b3f4a186cb76415054
Author: Andy Wingo <address@hidden>
Date:   Wed Nov 16 23:13:55 2011 +0100

    hack the port-column of current-output-port after printing a prompt
    
    * module/ice-9/boot-9.scm (repl-reader): Reset the output-column to 0
      after printing the prompt.  Fixes bug 9664.

-----------------------------------------------------------------------

Summary of changes:
 module/ice-9/boot-9.scm |   21 ++++++++++++++++++++-
 1 files changed, 20 insertions(+), 1 deletions(-)

diff --git a/module/ice-9/boot-9.scm b/module/ice-9/boot-9.scm
index a1ec5cc..653c693 100644
--- a/module/ice-9/boot-9.scm
+++ b/module/ice-9/boot-9.scm
@@ -2923,7 +2923,26 @@ module '(ice-9 q) '(make-q q-length))}."
 (define repl-reader
   (lambda* (prompt #:optional (reader (fluid-ref current-reader)))
     (if (not (char-ready?))
-        (display (if (string? prompt) prompt (prompt))))
+        (begin
+          (display (if (string? prompt) prompt (prompt)))
+          ;; An interesting situation.  The printer resets the column to
+          ;; 0 by printing a newline, but we then advance it by printing
+          ;; the prompt.  However the port-column of the output port
+          ;; does not typically correspond with the actual column on the
+          ;; screen, because the input is is echoed back!  Since the
+          ;; input is line-buffered and thus ends with a newline, the
+          ;; output will really start on column zero.  So, here we zero
+          ;; it out.  See bug 9664.
+          ;;
+          ;; Note that for similar reasons, the output-line will not
+          ;; reflect the actual line on the screen.  But given the
+          ;; possibility of multiline input, the fix is not as
+          ;; straightforward, so we don't bother.
+          ;;
+          ;; Also note that the readline implementation papers over
+          ;; these concerns, because it's readline itself printing the
+          ;; prompt, and not Guile.
+          (set-port-column! (current-output-port) 0)))
     (force-output)
     (run-hook before-read-hook)
     ((or reader read) (current-input-port))))


hooks/post-receive
-- 
GNU Guile