Merge branch 'smoke-me/ilmari/exec-empty-argv' into blead

4 files changed, 37 insertions, 15 deletions

diff --git a/doio.c b/doio.c
index 7b6c43531b..a12f8dc8a9 100644
--- a/doio.c
+++ b/doio.c
@@ -1924,7 +1924,8 @@ Perl_do_aexec5(pTHX_ SV *really, SV **mark, SV **sp,
 #if defined(__SYMBIAN32__) || defined(__LIBCATAMOUNT__)
     Perl_croak(aTHX_ "exec? I'm not *that* kind of operating system");
 #else
-    if (sp > mark) {
+    assert(sp >= mark);
+    {
 	const char **a;
 	const char *tmps = NULL;
 	Newx(PL_Argv, sp - mark + 1, const char*);
@@ -1939,17 +1940,19 @@ Perl_do_aexec5(pTHX_ SV *really, SV **mark, SV **sp,
 	*a = NULL;
 	if (really)
 	    tmps = SvPV_nolen_const(really);
-	if ((!really && *PL_Argv[0] != '/') ||
+        if ((!really && PL_Argv[0] && *PL_Argv[0] != '/') ||
 	    (really && *tmps != '/'))		/* will execvp use PATH? */
 	    TAINT_ENV();		/* testing IFS here is overkill, probably */
 	PERL_FPU_PRE_EXEC
 	if (really && *tmps) {
             PerlProc_execvp(tmps,EXEC_ARGV_CAST(PL_Argv));
-	} else {
+        } else if (PL_Argv[0]) {
             PerlProc_execvp(PL_Argv[0],EXEC_ARGV_CAST(PL_Argv));
-	}
+        } else {
+            SETERRNO(ENOENT,RMS_FNF);
+        }
 	PERL_FPU_POST_EXEC
- 	S_exec_failed(aTHX_ (really ? tmps : PL_Argv[0]), fd, do_report);
+        S_exec_failed(aTHX_ (really ? tmps : PL_Argv[0] ? PL_Argv[0] : ""), fd, do_report);
     }
     do_execfree();
 #endif
diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index c0beb063ee..d93050733f 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -362,7 +362,11 @@ files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
 
 =item *
 
-XXX
+Calling L<exec PROGRAM LIST|perlfunc/exec PROGRAM LIST> with an empty C<LIST>
+has been fixed.  This should call C<execvp()> with an empty C<argv> array
+(containing only the terminating C<NULL> pointer), but was instead just
+returning false (and not setting L<C<$!>|perlvar/$!>).
+L<[perl #131730]|https://rt.perl.org/Public/Bug/Display.html?id=131730>
 
 =back
 
diff --git a/t/op/exec.t b/t/op/exec.t
index 11554395b9..5a0f7b5601 100644
--- a/t/op/exec.t
+++ b/t/op/exec.t
@@ -36,7 +36,7 @@ $ENV{LANGUAGE} = 'C';		# Ditto in GNU.
 my $Is_VMS   = $^O eq 'VMS';
 my $Is_Win32 = $^O eq 'MSWin32';
 
-plan(tests => 25);
+plan(tests => 29);
 
 my $Perl = which_perl();
 
@@ -156,6 +156,21 @@ TODO: {
         "exec failure doesn't terminate process");
 }
 
+{
+    local $! = 0;
+    ok !exec(), 'empty exec LIST fails';
+    ok $! == 2 || $! =~ qr/\bno\b.*\bfile\b/i, 'errno = ENOENT'
+        or printf "# \$! eq %d, '%s'\n", $!, $!;
+
+}
+{
+    local $! = 0;
+    my $err = $!;
+    ok !(exec {""} ()), 'empty exec PROGRAM LIST fails';
+    ok $! == 2 || $! =~ qr/\bno\b.*\bfile\b/, 'errno = ENOENT'
+        or printf "# \$! eq %d, '%s'\n", $!, $!;
+}
+
 my $test = curr_test();
 exec $Perl, '-le', qq{${quote}print 'ok $test - exec PROG, LIST'${quote}};
 fail("This should never be reached if the exec() worked");
diff --git a/vms/vms.c b/vms/vms.c
index 5ca4d7c0e3..df0aed85b7 100644
--- a/vms/vms.c
+++ b/vms/vms.c
@@ -10953,16 +10953,16 @@ Perl_vms_do_aexec(pTHX_ SV *really,SV **mark,SV **sp)
   bool exec_sts;
   char * cmd;
 
-  if (sp > mark) {
-    if (vfork_called) {           /* this follows a vfork - act Unixish */
-      vfork_called--;
-      if (vfork_called < 0) {
-        Perl_warn(aTHX_ "Internal inconsistency in tracking vforks");
-        vfork_called = 0;
-      }
-      else return do_aexec(really,mark,sp);
+  if (vfork_called) {           /* this follows a vfork - act Unixish */
+    vfork_called--;
+    if (vfork_called < 0) {
+      Perl_warn(aTHX_ "Internal inconsistency in tracking vforks");
+      vfork_called = 0;
     }
+    else return do_aexec(really,mark,sp);
+  }
                                            /* no vfork - act VMSish */
+  if (sp > mark) {
     cmd = setup_argstr(aTHX_ really,mark,sp);
     exec_sts = vms_do_exec(cmd);
     Safefree(cmd);  /* Clean up from setup_argstr() */