From c79f3527498974c328404ed6807f9aaa5608832e Mon Sep 17 00:00:00 2001 From: =?utf8?q?P=C3=A1draig=20Brady?= Date: Fri, 29 May 2015 03:11:59 +0100 Subject: [PATCH] linkat: avoid OS X 10.10 trailing slash with symlink bug On Darwin 14.3.0 linkat(,"path1",,"dangling_symlink/",) causes the symlink to be dereferenced, and if it points to a non existent file, that file will be created as a hard link to "path1". This fixes a test failure in test-linkat.c. * m4/linkat.m4 (gl_FUNC_LINKAT): Augment the test with this case. The existing workaround in linkat.c for trailing slash issues, suffices for this case. * doc/posix-functions/linkat.texi: Add OS X 10.10 to the list of platforms with trailing slash issues. --- ChangeLog | 14 ++++++++++++++ doc/posix-functions/linkat.texi | 2 +- m4/linkat.m4 | 14 ++++++++++++-- 3 files changed, 27 insertions(+), 3 deletions(-) diff --git a/ChangeLog b/ChangeLog index 035fb7aefd..82abe7f8a3 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,17 @@ +2015-05-29 Pádraig Brady + + linkat: avoid OS X 10.10 trailing slash with symlink bug + On Darwin 14.3.0 linkat(,"path1",,"dangling_symlink/",) + causes the symlink to be dereferenced, and if it points + to a non existent file, that file will be created as + a hard link to "path1". + This fixes a test failure in test-linkat.c. + * m4/linkat.m4 (gl_FUNC_LINKAT): Augment the test with + this case. The existing workaround in linkat.c for + trailing slash issues, suffices for this case. + * doc/posix-functions/linkat.texi: Add OS X 10.10 to + the list of platforms with trailing slash issues. + 2015-05-28 Pádraig Brady unlinkat: handle ignoring of ".." on Darwin 14 diff --git a/doc/posix-functions/linkat.texi b/doc/posix-functions/linkat.texi index fadb350ab5..8bdf9d378f 100644 --- a/doc/posix-functions/linkat.texi +++ b/doc/posix-functions/linkat.texi @@ -19,7 +19,7 @@ Mac OS X 10.10. @item This function fails to reject trailing slashes on non-directories on some platforms: -AIX 7.1, Solaris 11 2011-11. +AIX 7.1, Solaris 11 2011-11, Mac OS X 10.10. @item This functions does not support @code{AT_SYMLINK_FOLLOW} on some platforms: Linux kernel 2.6.17. diff --git a/m4/linkat.m4 b/m4/linkat.m4 index 567cb5dcaa..03cf23a2e4 100644 --- a/m4/linkat.m4 +++ b/m4/linkat.m4 @@ -52,7 +52,7 @@ AC_DEFUN([gl_FUNC_LINKAT], AC_CACHE_CHECK([whether linkat handles trailing slash correctly], [gl_cv_func_linkat_slash], - [rm -rf conftest.a conftest.b conftest.c conftest.d + [rm -rf conftest.a conftest.b conftest.c conftest.d conftest.e conftest.s AC_RUN_IFELSE( [AC_LANG_PROGRAM( [[#include @@ -83,6 +83,16 @@ AC_DEFUN([gl_FUNC_LINKAT], if (linkat (AT_FDCWD, "conftest.a", AT_FDCWD, "conftest.d/", AT_SYMLINK_FOLLOW) == 0) result |= 8; + + /* On OS X 10.10 a trailing "/" will cause the second path to be + dereferenced, and thus will succeed on a dangling symlink. */ + if (symlink ("conftest.e", "conftest.s") == 0) + { + if (linkat (AT_FDCWD, "conftest.a", AT_FDCWD, "conftest.s/", + AT_SYMLINK_FOLLOW) == 0) + result |= 16; + } + return result; ]])], [gl_cv_func_linkat_slash=yes], @@ -93,7 +103,7 @@ AC_DEFUN([gl_FUNC_LINKAT], *) gl_cv_func_linkat_slash="guessing no";; esac ]) - rm -rf conftest.a conftest.b conftest.c conftest.d]) + rm -rf conftest.a conftest.b conftest.c conftest.d conftest.e conftest.s]) case "$gl_cv_func_linkat_slash" in *yes) gl_linkat_slash_bug=0 ;; *) gl_linkat_slash_bug=1 ;; -- 2.39.5