rpl_unlink sets errno to EPERM on malloc failure

rpl_unlink sets errno to EPERM on malloc failure

[Tim Rühsen]

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Is this EPERM intended ? If yes, there should be a comment.

lib/unlink.c (rpl_unlink):
          /* Trailing NUL will overwrite the trailing slash.  */
          char *short_name = malloc (len);
          if (!short_name)
            {
              errno = EPERM;
              return -1;
            }

Regards, Tim


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Re: rpl_unlink sets errno to EPERM on malloc failure

[Paul Eggert]

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On 3/20/20 4:54 AM, Tim Rühsen wrote:
> Is this EPERM intended ?

No, it's clearly a typo. Thanks for reporting it. I installed the attached.

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From 3e89c500a2f17a8a7a278390d48419990ce24bc8 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sat, 21 Mar 2020 16:13:28 -0700
Subject: [PATCH] unlink: fix malloc errno typo
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Problem reported by Tim Rühsen in:
https://lists.gnu.org/r/bug-gnulib/2020-03/msg00044.html
* lib/unlink.c (rpl_unlink): Don’t mask malloc errno.
---
 ChangeLog    | 7 +++++++
 lib/unlink.c | 5 +----
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 0019334ca..9b2a112eb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2020-03-21  Paul Eggert  <eggert@cs.ucla.edu>
+
+	unlink: fix malloc errno typo
+	Problem reported by Tim Rühsen in:
+	https://lists.gnu.org/r/bug-gnulib/2020-03/msg00044.html
+	* lib/unlink.c (rpl_unlink): Don’t mask malloc errno.
+
 2020-03-16  Bruno Haible  <bruno@clisp.org>
 
 	*printf-posix: Fix m4 error (regression from 2020-03-08).
diff --git a/lib/unlink.c b/lib/unlink.c
index b7daa7cd3..5e0f4e177 100644
--- a/lib/unlink.c
+++ b/lib/unlink.c
@@ -65,10 +65,7 @@ rpl_unlink (char const *name)
           /* Trailing NUL will overwrite the trailing slash.  */
           char *short_name = malloc (len);
           if (!short_name)
-            {
-              errno = EPERM;
-              return -1;
-            }
+            return -1;
           memcpy (short_name, name, len);
           while (len && ISSLASH (short_name[len - 1]))
             short_name[--len] = '\0';
-- 
2.17.1

Re: rpl_unlink sets errno to EPERM on malloc failure

[Bruno Haible]

Paul Eggert wrote:
--- a/lib/unlink.c
+++ b/lib/unlink.c
@@ -65,10 +65,7 @@ rpl_unlink (char const *name)
           /* Trailing NUL will overwrite the trailing slash.  */
           char *short_name = malloc (len);
           if (!short_name)
-            {
-              errno = EPERM;
-              return -1;
-            }
+            return -1;
           memcpy (short_name, name, len);
           while (len && ISSLASH (short_name[len - 1]))
             short_name[--len] = '\0';

But while on POSIX systems, malloc() is guaranteed to set errno when it fails,
for native Windows systems we need the 'malloc-posix' module, in order to
guarantee this.


2020-03-21  Bruno Haible  <bruno@clisp.org>

	unlink: Ensure errno also on native Windows.
	* modules/unlink (Depends-on): Add malloc-posix.

diff --git a/modules/unlink b/modules/unlink
index 63720aa..5fc84d9 100644
--- a/modules/unlink
+++ b/modules/unlink
@@ -9,6 +9,7 @@ Depends-on:
 unistd
 dosname         [test $REPLACE_UNLINK = 1]
 lstat           [test $REPLACE_UNLINK = 1]
+malloc-posix    [test $REPLACE_UNLINK = 1]
 
 configure.ac:
 gl_FUNC_UNLINK