From 3dfcac940930a8aa6779f5debea6ea6357372419 Mon Sep 17 00:00:00 2001
From: Daniel Dragan <bulk88@hotmail.com>
Date: Sun, 16 Aug 2015 04:30:23 -0400
Subject: [PATCH] fix do dir returning no $!
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do()ing a directory was returning false/empty string in $!, which isn't
an error, yet documentation says $! should have the error code in it.
Fix this by returning EISDIR for dirs, and EINVAL for block devices.
[perl #125774]

Remove "errno = 0" and comment added in b2da7ead68, since now there is no
scenario where errno is uninitialized, since the dir and block device
failure branches now set errno, where previously they didn't.

Petr Písař: Ported to 5.26.1.

Signed-off-by: Petr Písař <ppisar@redhat.com>
---
 pp_ctl.c  | 25 +++++++++++++++++--------
 t/op/do.t | 14 +++++++++++++-
 2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/pp_ctl.c b/pp_ctl.c
index e24d7b6..f136f91 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -3534,15 +3534,22 @@ S_check_type_and_open(pTHX_ SV *name)
        errno EACCES, so only do a stat to separate a dir from a real EACCES
        caused by user perms */
 #ifndef WIN32
-    /* we use the value of errno later to see how stat() or open() failed.
-     * We don't want it set if the stat succeeded but we still failed,
-     * such as if the name exists, but is a directory */
-    errno = 0;
-
     st_rc = PerlLIO_stat(p, &st);
 
-    if (st_rc < 0 || S_ISDIR(st.st_mode) || S_ISBLK(st.st_mode)) {
+    if (st_rc < 0)
 	return NULL;
+    else {
+	int eno;
+	if(S_ISBLK(st.st_mode)) {
+	    eno = EINVAL;
+	    goto not_file;
+	}
+	else if(S_ISDIR(st.st_mode)) {
+	    eno = EISDIR;
+	    not_file:
+	    errno = eno;
+	    return NULL;
+	}
     }
 #endif
 
@@ -3554,8 +3561,10 @@ S_check_type_and_open(pTHX_ SV *name)
 	int eno;
 	st_rc = PerlLIO_stat(p, &st);
 	if (st_rc >= 0) {
-	    if(S_ISDIR(st.st_mode) || S_ISBLK(st.st_mode))
-		eno = 0;
+	    if(S_ISDIR(st.st_mode))
+		eno = EISDIR;
+	    else if(S_ISBLK(st.st_mode))
+		eno = EINVAL;
 	    else
 		eno = EACCES;
 	    errno = eno;
diff --git a/t/op/do.t b/t/op/do.t
index 78d8800..1c54f0b 100644
--- a/t/op/do.t
+++ b/t/op/do.t
@@ -7,6 +7,7 @@ BEGIN {
 }
 use strict;
 no warnings 'void';
+use Errno qw(ENOENT EISDIR);
 
 my $called;
 my $result = do{ ++$called; 'value';};
@@ -247,7 +248,7 @@ SKIP: {
     my $saved_errno = $!;
     ok(!$rv,          "do returns false on io errror");
     ok(!$saved_error, "\$\@ not set on io error");
-    ok($saved_errno,  "\$! set on io error");
+    ok($saved_errno == ENOENT, "\$! is ENOENT for nonexistent file");
 }
 
 # do subname should not be do "subname"
@@ -305,4 +306,15 @@ SKIP: {
 }
 
 
+# do file $!s must be correct
+{
+    local @INC = ('.'); #want EISDIR not ENOENT
+    my $rv = do 'op'; # /t/op dir
+    my $saved_error = $@;
+    my $saved_errno = $!+0;
+    ok(!$rv,                    "do dir returns false");
+    ok(!$saved_error,           "\$\@ is false on do dir");
+    ok($saved_errno == EISDIR,  "\$! is EISDIR on do dir");
+}
+
 done_testing();
-- 
2.13.6