Merge from gnulib.

2 files changed, 19 insertions, 6 deletions

diff --git a/lib/sys_select.in.h b/lib/sys_select.in.h
index 521ccef321d..2af6bfe6f6f 100644
--- a/lib/sys_select.in.h
+++ b/lib/sys_select.in.h
@@ -21,23 +21,27 @@
 
 /* On OSF/1 and Solaris 2.6, <sys/types.h> and <sys/time.h>
    both include <sys/select.h>.
+   On Cygwin, <sys/time.h> includes <sys/select.h>.
    Simply delegate to the system's header in this case.  */
 #if (@HAVE_SYS_SELECT_H@                                                \
-     && ((defined __osf__ && defined _SYS_TYPES_H_ && defined _OSF_SOURCE) \
+     && ((defined __osf__ && defined _SYS_TYPES_H_                      \
+          && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H         \
+          && defined _OSF_SOURCE)                                       \
          || (defined __sun && defined _SYS_TYPES_H                      \
              && (! (defined _XOPEN_SOURCE || defined _POSIX_C_SOURCE)   \
-                 || defined __EXTENSIONS__)))                           \
-     && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H)
+                 || defined __EXTENSIONS__))))
 
 # define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H
 # @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
 
 #elif (@HAVE_SYS_SELECT_H@                                              \
-       && ((defined __osf__ && defined _SYS_TIME_H_ && defined _OSF_SOURCE) \
+       && (defined _CYGWIN_SYS_TIME_H                                   \
+           || (defined __osf__ && defined _SYS_TIME_H_                  \
+               && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H    \
+               && defined _OSF_SOURCE)                                  \
            || (defined __sun && defined _SYS_TIME_H                     \
                && (! (defined _XOPEN_SOURCE || defined _POSIX_C_SOURCE) \
-                   || defined __EXTENSIONS__)))                         \
-       && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H)
+                   || defined __EXTENSIONS__))))
 
 # define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H
 # @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
diff --git a/lib/sys_time.in.h b/lib/sys_time.in.h
index 656c3f13ad2..3dbf6320667 100644
--- a/lib/sys_time.in.h
+++ b/lib/sys_time.in.h
@@ -24,6 +24,14 @@
 #endif
 @PRAGMA_COLUMNS@
 
+/* On Cygwin, <sys/time.h> includes itself recursively via <sys/select.h>.
+   Simply delegate to the system's header in this case; it is a no-op.
+   Without this extra ifdef, the C++ gettimeofday declaration below
+   would be a forward declaration in gnulib's nested <sys/time.h>.  */
+#ifdef _CYGWIN_SYS_TIME_H
+# @INCLUDE_NEXT@ @NEXT_SYS_TIME_H@
+#else
+
 /* The include_next requires a split double-inclusion guard.  */
 #if @HAVE_SYS_TIME_H@
 # @INCLUDE_NEXT@ @NEXT_SYS_TIME_H@
@@ -200,4 +208,5 @@ _GL_WARN_ON_USE (gettimeofday, "gettimeofday is unportable - "
 #endif
 
 #endif /* _@GUARD_PREFIX@_SYS_TIME_H */
+#endif /* _CYGWIN_SYS_TIME_H */
 #endif /* _@GUARD_PREFIX@_SYS_TIME_H */