From: Walter Alejandro Iglesias <wai@roquesor.com>
Subject: This is indeed a bug (ex Re: vi E_CLRFLAG not being used correctly?)
To: Jeremy Mates <jmates@thrig.me>
Cc: tech@openbsd.org
Date: Wed, 4 Feb 2026 15:39:36 +0100

On Sat, Jan 31, 2026 at 12:59:35AM +0000, Jeremy Mates wrote:
> 	$ printf 'append\na\nb\nc\n.\nnumber\nnumber l\nq!\n' | ex         
> 		 3  c
> 		 3  c$
> 	c$
> 
> In ex mode, the "number" command when given the "l" (literal display)
> flag causes an additional line to be printed by the autoprint code in
> ex/ex.c. The autoprint code tries to turn off the various flags when
> E_CLRFLAG is set by an ex command. However, it appears that E_CLRFLAG is
> put into ecp->flags ("current flags") from the command flags,
> 
>     /* Add standard command flags. */
>     F_SET(ecp, ecp->cmd->flags);
> 
> while the ex/ex.c autoprint code instead checks ecp->iflags ("User input
> information") for E_CLRFLAG, hence the "number l" command causing an
> additional ex_print line, as E_C_LIST is not turned off.
> 
>         /*
>          * The print commands have already handled the `print' flags.
>          * If so, clear them.
>          */
>         if (FL_ISSET(ecp->iflags, E_CLRFLAG))
>             FL_CLR(ecp->iflags, E_C_HASH | E_C_LIST | E_C_PRINT);
> 
> A fix might be to use ->flags (where E_CLRFLAG is) instead of ->iflags?
> 
> --- ex/ex.c
> +++ ex/ex.c
> @@ -1439,7 +1439,7 @@ addr_verify:
>  		 * The print commands have already handled the `print' flags.
>  		 * If so, clear them.
>  		 */
> -		if (FL_ISSET(ecp->iflags, E_CLRFLAG))
> +		if (FL_ISSET(ecp->flags, E_CLRFLAG))
>  			FL_CLR(ecp->iflags, E_C_HASH | E_C_LIST | E_C_PRINT);
>  
>  		/* If hash set only because of the number option, discard it. */
> 
> 


The E_CLRFLAG is defined in ex/ex.h as hexadecimal '80':

  $ grep -Ir /usr/src/usr.bin/vi '^#define.*E_CLRFLAG'
  ex/ex.h:#define E_CLRFLAG       0x00000080      /* Clear the print (#, l, p) flags. */

If you compile vi(1) after appling this test diff:

Index: ex/ex.c
===================================================================
RCS file: /cvs/src/usr.bin/vi/ex/ex.c,v
diff -u -p -u -p -r1.23 ex.c
--- ex/ex.c	23 Jun 2023 15:06:45 -0000	1.23
+++ ex/ex.c	4 Feb 2026 14:02:49 -0000
@@ -1439,7 +1439,17 @@ addr_verify:
 		 * The print commands have already handled the `print' flags.
 		 * If so, clear them.
 		 */
-		if (FL_ISSET(ecp->iflags, E_CLRFLAG))
+
+		/* -------------- TEST -------------------------- */
+		printf("F_ISSET(ecp, E_CLRFLAG) = %x\n",
+		    F_ISSET(ecp, E_CLRFLAG));
+		printf("FL_ISSET(ecp->iflags, E_CLRFLAG) = %x\n",
+		    FL_ISSET(ecp->iflags, E_CLRFLAG));
+		printf("FL_ISSET(ecp->flags, E_CLRFLAG) = %x\n",
+		    FL_ISSET(ecp->flags, E_CLRFLAG));
+		/* ------------------------------------------------ */
+
+		if (F_ISSET(ecp, E_CLRFLAG))
 			FL_CLR(ecp->iflags, E_C_HASH | E_C_LIST | E_C_PRINT);
 
 		/* If hash set only because of the number option, discard it. */


And then you run:

  (You can replace the command 'l' for '#', 'p' or any
   combination of them)
                      \
  $ printf 'i\nfoo\n.\nl\nq!\n' | ex
  F_ISSET(ecp, E_CLRFLAG) = 0
  FL_ISSET(ecp->iflags, E_CLRFLAG) = 0
  FL_ISSET(ecp->flags, E_CLRFLAG) = 0
  foo$
  F_ISSET(ecp, E_CLRFLAG) = 80
  FL_ISSET(ecp->iflags, E_CLRFLAG) = 0
  FL_ISSET(ecp->flags, E_CLRFLAG) = 80
  F_ISSET(ecp, E_CLRFLAG) = 0
  FL_ISSET(ecp->iflags, E_CLRFLAG) = 0
  FL_ISSET(ecp->flags, E_CLRFLAG) = 0

You see that from the three conditions (I added third one[1])
this one isn't useful:

  FL_ISSET(ecp->iflags, E_CLRFLAG) = 0

This confirms that what Jeremy found is indeed a bug and his proposed
diff fixes it.  Below I include a optional diff[1] using as condition
F_ISSET(ecp, E_CLRFLAG) which, in my oppinion, follows the idiom of the
rest of the code.


Index: ex/ex.c
===================================================================
RCS file: /cvs/src/usr.bin/vi/ex/ex.c,v
diff -u -p -u -p -r1.23 ex.c
--- ex/ex.c	23 Jun 2023 15:06:45 -0000	1.23
+++ ex/ex.c	4 Feb 2026 14:19:26 -0000
@@ -1439,7 +1439,7 @@ addr_verify:
 		 * The print commands have already handled the `print' flags.
 		 * If so, clear them.
 		 */
-		if (FL_ISSET(ecp->iflags, E_CLRFLAG))
+		if (F_ISSET(ecp, E_CLRFLAG))
 			FL_CLR(ecp->iflags, E_C_HASH | E_C_LIST | E_C_PRINT);
 
 		/* If hash set only because of the number option, discard it. */




-- 
Walter