# HG changeset patch
# User Paul Eggert <eggert@penguin.cs.ucla.edu>
# Date 1393355787 28800
# Node ID 86af85d364e1e22a1cfbb90fa8b852844e7b3de7
# Parent  0dd22c534074c91932abe30a6519ff91bb0da20c
unistd: port readlink to Mac OS X 10.3.9

* lib/unistd.in.h (_GL_INCLUDING_UNISTD_H): New macro, to work
around self-include problem in Mac OS X 10.3.9 when combined with
readlink module.  Problem reported by Klaus Zietler in
<http://bugs.gnu.org/16825>.

diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2014-02-25  Paul Eggert  <eggert@penguin.cs.ucla.edu>
+
+	unistd: port readlink to Mac OS X 10.3.9
+	* lib/unistd.in.h (_GL_INCLUDING_UNISTD_H): New macro, to work
+	around self-include problem in Mac OS X 10.3.9 when combined with
+	readlink module.  Problem reported by Klaus Zietler in
+	<http://bugs.gnu.org/16825>.
+
 2014-02-23  Paul Eggert  <eggert@cs.ucla.edu>
 
 	diffseq: remove TOO_EXPENSIVE heuristic
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -21,9 +21,23 @@
 #endif
 @PRAGMA_COLUMNS@
 
+#ifdef _GL_INCLUDING_UNISTD_H
+/* Special invocation convention:
+   - On Mac OS X 10.3.9 we have a sequence of nested includes
+     <unistd.h> -> <signal.h> -> <pthread.h> -> <unistd.h>
+     In this situation, the functions are not yet declared, therefore we cannot
+     provide the C++ aliases.  */
+
+#@INCLUDE_NEXT@ @NEXT_UNISTD_H@
+
+#else
+/* Normal invocation convention.  */
+
 /* The include_next requires a split double-inclusion guard.  */
 #if @HAVE_UNISTD_H@
+# define _GL_INCLUDING_UNISTD_H
 # @INCLUDE_NEXT@ @NEXT_UNISTD_H@
+# undef _GL_INCLUDING_UNISTD_H
 #endif
 
 /* Get all possible declarations of gethostname().  */
@@ -1539,4 +1553,5 @@
 _GL_INLINE_HEADER_END
 
 #endif /* _@GUARD_PREFIX@_UNISTD_H */
+#endif /* _GL_INCLUDING_UNISTD_H */
 #endif /* _@GUARD_PREFIX@_UNISTD_H */