The closing " of a string is omitted when truncation occurs due to *print-lines* in pretty-printed escaped output

[Jean-Philippe Paradis]

What I do:
(progn (write (format nil "This is~%a test.") :pretty t :escape t :lines 1)
       (values))

What happens:
Output:
"This is ..

What I expected to happen:
Output:
"This is .."

SBCL version: 1.0.42
uname -a: Linux dynamorph 2.6.32-30-generic #59-Ubuntu SMP Tue Mar 1 21:30:21 UTC 2011 i686 GNU/Linux

*features*:
(:SWANK :QUICKLISP :SB-BSD-SOCKETS-ADDRINFO :ASDF-UNIX :ASDF2 :ASDF :ANSI-CL
 :COMMON-LISP :SBCL :SB-DOC :SB-TEST :SB-LDB :SB-PACKAGE-LOCKS :SB-UNICODE
 :SB-EVAL :SB-SOURCE-LOCATIONS :IEEE-FLOATING-POINT :X86 :UNIX :ELF :LINUX
 :SB-THREAD :LARGEFILE :GENCGC :STACK-GROWS-DOWNWARD-NOT-UPWARD
 :C-STACK-IS-CONTROL-STACK :COMPARE-AND-SWAP-VOPS :UNWIND-TO-FRAME-AND-CALL-VOP
 :RAW-INSTANCE-INIT-VOPS :STACK-ALLOCATABLE-CLOSURES :STACK-ALLOCATABLE-VECTORS
 :STACK-ALLOCATABLE-LISTS :STACK-ALLOCATABLE-FIXED-OBJECTS :ALIEN-CALLBACKS
 :CYCLE-COUNTER :INLINE-CONSTANTS :MEMORY-BARRIER-VOPS :LINKAGE-TABLE
 :OS-PROVIDES-DLOPEN :OS-PROVIDES-PUTWC :OS-PROVIDES-SUSECONDS-T)

[Jean-Philippe Paradis (hexstream)]

Come to think of it, I think the output should be:
"This is.."

Is the additional space between "is" and ".." conforming and intentional?...

[Douglas Katzman (dougk)]

Two problems with this:
1. It's unclear how the pretty-printer should respond to fixed strings that contain mandatory newlines. i.e. it might not be correct to truncate in the first place.
2. It's unclear that strings have status as logical blocks. I see no implication in the spec that they do.
I tested the example in ABCL, ECL, Allegro, and LispWorks.
Half of them don't truncate (taking viewpoint 1), and half truncate but don't print a trailing quote (taking viewpoint 2).

[Jean-Philippe Paradis (hexstream)]

Thank you, I think this is the first non-insane WONTFIX I have ever
received, although I don't want to take the time to audit the others
to verify if this is indeed the case.

On Sat, Dec 12, 2020 at 3:04 PM Douglas Katzman
<email address hidden> wrote:
>
> Two problems with this:
> 1. It's unclear how the pretty-printer should respond to fixed strings that contain mandatory newlines. i.e. it might not be correct to truncate in the first place.
> 2. It's unclear that strings have status as logical blocks. I see no implication in the spec that they do.
> I tested the example in ABCL, ECL, Allegro, and LispWorks.
> Half of them don't truncate (taking viewpoint 1), and half truncate but don't print a trailing quote (taking viewpoint 2).
>
>
> ** Changed in: sbcl
> Status: Triaged => Won't Fix
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/768622
>
> Title:
> The closing " of a string is omitted when truncation occurs due to
> *print-lines* in pretty-printed escaped output
>
> Status in SBCL:
> Won't Fix
>
> Bug description:
> What I do:
> (progn (write (format nil "This is~%a test.") :pretty t :escape t :lines 1)
> (values))
>
> What happens:
> Output:
> "This is ..
>
> What I expected to happen:
> Output:
> "This is .."
>
> SBCL version: 1.0.42
> uname -a: Linux dynamorph 2.6.32-30-generic #59-Ubuntu SMP Tue Mar 1 21:30:21 UTC 2011 i686 GNU/Linux
>
> *features*:
> (:SWANK :QUICKLISP :SB-BSD-SOCKETS-ADDRINFO :ASDF-UNIX :ASDF2 :ASDF :ANSI-CL
> :COMMON-LISP :SBCL :SB-DOC :SB-TEST :SB-LDB :SB-PACKAGE-LOCKS :SB-UNICODE
> :SB-EVAL :SB-SOURCE-LOCATIONS :IEEE-FLOATING-POINT :X86 :UNIX :ELF :LINUX
> :SB-THREAD :LARGEFILE :GENCGC :STACK-GROWS-DOWNWARD-NOT-UPWARD
> :C-STACK-IS-CONTROL-STACK :COMPARE-AND-SWAP-VOPS :UNWIND-TO-FRAME-AND-CALL-VOP
> :RAW-INSTANCE-INIT-VOPS :STACK-ALLOCATABLE-CLOSURES :STACK-ALLOCATABLE-VECTORS
> :STACK-ALLOCATABLE-LISTS :STACK-ALLOCATABLE-FIXED-OBJECTS :ALIEN-CALLBACKS
> :CYCLE-COUNTER :INLINE-CONSTANTS :MEMORY-BARRIER-VOPS :LINKAGE-TABLE
> :OS-PROVIDES-DLOPEN :OS-PROVIDES-PUTWC :OS-PROVIDES-SUSECONDS-T)
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/sbcl/+bug/768622/+subscriptions