Port double-slash test to z/OS

* admin/merge-gnulib (GNULIB_MODULES): Add double-slash-root.
Emacs was already using this Gnulib module indirectly, so this
is merely noting that there is now a direct dependency.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* src/fileio.c (search_embedded_absfilename):
Use DOUBLE_SLASH_IS_DISTINCT_ROOT instead of (WINDOWSNT || CYGWIN).
Simplify.

1 files changed, 10 insertions, 12 deletions

diff --git a/src/fileio.c b/src/fileio.c
index 4c7625cad4a..e4269b96a37 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -1778,20 +1778,18 @@ get_homedir (void)
 static char *
 search_embedded_absfilename (char *nm, char *endp)
 {
-  char *p, *s;
-
-  for (p = nm + 1; p < endp; p++)
+  char *p = nm + 1;
+#ifdef DOUBLE_SLASH_IS_DISTINCT_ROOT
+  p += (IS_DIRECTORY_SEP (p[-1]) && IS_DIRECTORY_SEP (p[0])
+        && !IS_DIRECTORY_SEP (p[1]));
+#endif
+  for (; p < endp; p++)
     {
-      if (IS_DIRECTORY_SEP (p[-1])
-          && file_name_absolute_p (p)
-#if defined (WINDOWSNT) || defined (CYGWIN)
-          /* // at start of file name is meaningful in Apollo,
-             WindowsNT and Cygwin systems.  */
-          && !(IS_DIRECTORY_SEP (p[0]) && p - 1 == nm)
-#endif /* not (WINDOWSNT || CYGWIN) */
-          )
+      if (IS_DIRECTORY_SEP (p[-1]) && file_name_absolute_p (p))
         {
-          for (s = p; *s && !IS_DIRECTORY_SEP (*s); s++);
+          char *s;
+          for (s = p; *s && !IS_DIRECTORY_SEP (*s); s++)
+            continue;
           if (p[0] == '~' && s > p + 1) /* We've got "/~something/".  */
             {
               USE_SAFE_ALLOCA;