sanity check piped opens (tweaked version of patch suggested

by Mark-Jason Dominus)

p4raw-id: //depot/perl@2629

6 files changed, 52 insertions, 3 deletions

diff --git a/doio.c b/doio.c
index 641046b731..48e6c62fbf 100644
--- a/doio.c
+++ b/doio.c
@@ -188,6 +188,13 @@ do_open(GV *gv, register char *name, I32 len, int as_raw, int rawmode, int rawpe
 	if (*name == '|') {
 	    /*SUPPRESS 530*/
 	    for (name++; isSPACE(*name); name++) ;
+	    if (*name == '\0') { /* command is missing 19990114 */
+		dTHR;
+		if (ckWARN(WARN_PIPE))
+		    warner(WARN_PIPE, "Missing command in piped open");
+		errno = EPIPE;
+		goto say_false;
+	    }
 	    if (strNE(name,"-"))
 		TAINT_ENV();
 	    TAINT_PROPER("piped open");
@@ -285,6 +292,13 @@ do_open(GV *gv, register char *name, I32 len, int as_raw, int rawmode, int rawpe
 		name[--len] = '\0';
 	    /*SUPPRESS 530*/
 	    for (; isSPACE(*name); name++) ;
+	    if (*name == '\0') { /* command is missing 19990114 */
+		dTHR;
+		if (ckWARN(WARN_PIPE))
+		    warner(WARN_PIPE, "Missing command in piped open");
+		errno = EPIPE;
+		goto say_false;
+	    }
 	    if (strNE(name,"-"))
 		TAINT_ENV();
 	    TAINT_PROPER("piped open");
diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index bd2b715605..afe29e689e 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -140,6 +140,11 @@ C<'>-delimited regular expression.
 (W) You used a backslash-character combination which is not recognized
 by Perl.
 
+=item Missing command in piped open
+
+(W) You used the C<open(FH, "| command")> or C<open(FH, "command |")>
+construction, but the command was missing or blank.
+
 =head1 Obsolete Diagnostics
 
 Todo.
diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index e0e9b128e9..211262c626 100644
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -1546,6 +1546,11 @@ one line to the next.
 (F) While certain functions allow you to specify a filehandle or an
 "indirect object" before the argument list, this ain't one of them.
 
+=item Missing command in piped open
+
+(W) You used the C<open(FH, "| command")> or C<open(FH, "command |")>
+construction, but the command was missing or blank.
+
 =item Missing operator before %s?
 
 (S) This is an educated guess made in conjunction with the message "%s
diff --git a/t/io/pipe.t b/t/io/pipe.t
index 08b312aec5..13db20b0c9 100755
--- a/t/io/pipe.t
+++ b/t/io/pipe.t
@@ -13,7 +13,7 @@ BEGIN {
 }
 
 $| = 1;
-print "1..12\n";
+print "1..14\n";
 
 # External program 'tr' assumed.
 open(PIPE, "|-") || (exec 'tr', 'YX', 'ko');
@@ -151,3 +151,10 @@ if ($? == 37*256 && $wait == $zombie && ! $!) {
 } else {
     print "not ok 12\n# pid=$wait first=$pid pipe=$pipe zombie=$zombie me=$$ \$?=$?   \$!=", $!+0, ":$!\n";
 }
+
+# Test new semantics for missing command in piped open
+# 19990114 M-J. Dominus mjd@plover.com
+{ local *P;
+  print (((open P, "|    " ) ? "not " : ""), "ok 13\n");
+  print (((open P, "     |" ) ? "not " : ""), "ok 14\n");
+}
diff --git a/t/op/taint.t b/t/op/taint.t
index 379093f587..e77d5d1a04 100755
--- a/t/op/taint.t
+++ b/t/op/taint.t
@@ -383,10 +383,10 @@ else {
 	for (76..79) { print "ok $_ # Skipped: open('|') is not available\n" }
     }
     else {
-	test 76, eval { open FOO, "| $foo" } eq '', 'popen to';
+	test 76, eval { open FOO, "| x$foo" } eq '', 'popen to';
 	test 77, $@ =~ /^Insecure dependency/, $@;
 
-	test 78, eval { open FOO, "$foo |" } eq '', 'popen from';
+	test 78, eval { open FOO, "x$foo |" } eq '', 'popen from';
 	test 79, $@ =~ /^Insecure dependency/, $@;
     }
 
diff --git a/t/pragma/warn/doio b/t/pragma/warn/doio
index 5e15c8c30f..41ac89a8e0 100644
--- a/t/pragma/warn/doio
+++ b/t/pragma/warn/doio
@@ -3,6 +3,12 @@
   Can't do bidirectional pipe
     open(F, "| true |");
 
+  Missing command in piped open
+    open(F, "| ");
+
+  Missing command in piped open
+    open(F, " |");
+
   warn(warn_nl, "open");
     open(F, "true\ncd")
 
@@ -44,6 +50,18 @@ Can't do bidirectional pipe at - line 3.
 ########
 # doio.c
 use warning 'io' ;
+open(F, "|      ")
+EXPECT
+Missing command in piped open at - line 3.
+########
+# doio.c
+use warning 'io' ;
+open(F, "      |")
+EXPECT
+Missing command in piped open at - line 3.
+########
+# doio.c
+use warning 'io' ;
 open(F, "<true\ncd")
 EXPECT
 Unsuccessful open on filename containing newline at - line 3.