Make $(< /nonexistent) have the same behaviour as $(cat /nonexistent)

wrt. errors (do not unwind and do not treat this as fatal if set -e is
used).  This matches what bash does.  Tweak regress tests while here.
ok millert@, jasper@ agrees

3 files changed, 24 insertions, 7 deletions

diff --git a/bin/ksh/eval.c b/bin/ksh/eval.c
index 28f6e79fe19..60aec522fd8 100644
--- a/bin/ksh/eval.c
+++ b/bin/ksh/eval.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: eval.c,v 1.38 2013/06/19 12:19:02 millert Exp $	*/
+/*	$OpenBSD: eval.c,v 1.39 2013/07/01 17:25:27 jca Exp $	*/
 
 /*
  * Expansion - quoting, separation, substitution, globbing
@@ -505,7 +505,9 @@ expand(char *cp,	/* input word */
 			break;
 
 		case XCOM:
-			if (newlines) {		/* Spit out saved nl's */
+			if (x.u.shf == NULL)	/* $(< ...) failed, fake EOF */
+				c = EOF;
+			else if (newlines) {		/* Spit out saved nl's */
 				c = '\n';
 				--newlines;
 			} else {
@@ -520,9 +522,12 @@ expand(char *cp,	/* input word */
 			}
 			if (c == EOF) {
 				newlines = 0;
-				shf_close(x.u.shf);
+				if (x.u.shf != NULL)
+					shf_close(x.u.shf);
 				if (x.split)
 					subst_exstat = waitlast();
+				else
+					subst_exstat = (x.u.shf == NULL);
 				type = XBASE;
 				if (f&DOBLANK)
 					doblank--;
@@ -860,7 +865,8 @@ comsub(Expand *xp, char *cp)
 		shf = shf_open(name = evalstr(io->name, DOTILDE), O_RDONLY, 0,
 			SHF_MAPHI|SHF_CLEXEC);
 		if (shf == NULL)
-			errorf("%s: cannot open $() input", name);
+			warningf(!Flag(FTALKING),
+			    "%s: cannot open $(<) input", name);
 		xp->split = 0;	/* no waitlast() */
 	} else {
 		int errexit, ofd1, pv[2];
diff --git a/bin/ksh/tests/obsd-regress.t b/bin/ksh/tests/obsd-regress.t
index 9338a0f4564..e545bcef93e 100644
--- a/bin/ksh/tests/obsd-regress.t
+++ b/bin/ksh/tests/obsd-regress.t
@@ -1,4 +1,4 @@
-#	$OpenBSD: obsd-regress.t,v 1.4 2013/06/19 14:04:42 millert Exp $
+#	$OpenBSD: obsd-regress.t,v 1.5 2013/07/01 17:25:27 jca Exp $
 
 #
 # ksh regression tests from OpenBSD
@@ -256,6 +256,16 @@ expected-stdout:
 	
 ---
 
+name: input-comsub
+description:
+	A command substitution using input redirection should exit with
+	failure if the input file does not exist.
+stdin:
+	var=$(< non-existent)
+expected-exit: e != 0
+expected-stderr-pattern: /non-existent/
+
+---
 name: empty-for-list
 description:
 	A for list which expands to zero items should not execute the body.
diff --git a/bin/ksh/tests/regress.t b/bin/ksh/tests/regress.t
index 264d415e0fe..e77df1a7432 100644
--- a/bin/ksh/tests/regress.t
+++ b/bin/ksh/tests/regress.t
@@ -1,4 +1,4 @@
-#	$OpenBSD: regress.t,v 1.14 2013/06/19 12:19:03 millert Exp $
+#	$OpenBSD: regress.t,v 1.15 2013/07/01 17:25:27 jca Exp $
 
 #
 # The first 39 of these tests are from the old Bugs script.
@@ -605,9 +605,10 @@ description:
 	set -e: errors in command substitutions aren't ignored
 arguments: !-e!
 stdin:
-	echo `false; echo hi`
+	echo `false; echo hi` $(< this-file-does-not-exist)
 expected-stdout:
 	hi
+expected-stderr-pattern: /this-file-does-not-exist/
 ---
 
 name: regression-40