[klibc] [EVAL] Fixed trap/return regression due to SKIPEVAL removal

On Wed, Aug 11, 2010 at 08:06:16AM +0000, Guido Berhoerster wrote:
>
> with the latest git version of dash trap actions are not
> evaluated in the context of a function.
>
> The following script demonstrates the bug:
> ----8<----
> read_timeout () {
>     saved_traps="$(trap)"
>     trap 'printf "timed out\n"; eval "${saved_traps}"; return' TERM
>     ( sleep $1; kill -TERM $$ ) >/dev/null 2>&1 &
>     timer_pid=$!
>     read $2
>     kill $timer_pid 2>/dev/null
> }
>
> read_timeout 5 value
> printf "read \"%s\"\n" "${value:=default}"
>
> ---->8----
> The return statement in the trap inside the read_timeout function
> does not return from the function but rather exits the script.
>
> With dash 0.5.5.1 it works as expected.

This bug was caused by the SKIPEVAL removal.  When the SKIPEVAL
hack was added to improve set -e support in traps, dotrap was
changed to return whether set -e was detected.  After the removal
of SKIPEVAL, set -e is now handled through exraise.

However, dotrap still returned a value which is now incorrectly
used to trigger an exraise.

This patch removes the vestigial link between dotrap and exraise.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: maximilian attems <max@stro.at>

3 files changed, 12 insertions, 9 deletions

diff --git a/usr/dash/eval.c b/usr/dash/eval.c
index cb331ebeda86e..ae4719a986c5a 100644
--- a/usr/dash/eval.c
+++ b/usr/dash/eval.c
@@ -304,10 +304,16 @@ setstatus:
 		break;
 	}
 out:
-	if ((checkexit & exitstatus) ||
-	    (pendingsigs && dotrap()) ||
-	    (flags & EV_EXIT))
+	if (checkexit & exitstatus)
+		goto exexit;
+
+	if (pendingsigs)
+		dotrap();
+
+	if (flags & EV_EXIT) {
+exexit:
 		exraise(EXEXIT);
+	}
 }
 
 
diff --git a/usr/dash/trap.c b/usr/dash/trap.c
index 67fda1ddfd58b..0014a1399f48b 100644
--- a/usr/dash/trap.c
+++ b/usr/dash/trap.c
@@ -308,8 +308,7 @@ onsig(int signo)
  * handlers while we are executing a trap handler.
  */
 
-int
-dotrap(void)
+void dotrap(void)
 {
 	char *p;
 	char *q;
@@ -331,10 +330,8 @@ dotrap(void)
 		evalstring(p, 0);
 		exitstatus = savestatus;
 		if (evalskip)
-			return evalskip;
+			break;
 	}
-
-	return 0;
 }
 
 
diff --git a/usr/dash/trap.h b/usr/dash/trap.h
index f98520fa40aeb..6590be1273e7b 100644
--- a/usr/dash/trap.h
+++ b/usr/dash/trap.h
@@ -46,7 +46,7 @@ void clear_traps(void);
 void setsignal(int);
 void ignoresig(int);
 void onsig(int);
-int dotrap(void);
+void dotrap(void);
 void setinteractive(int);
 void exitshell(void) __attribute__((__noreturn__));
 int decode_signal(const char *, int);