getcwd: fix compilation on mingw64

[gnulib.git] / lib / openat-proc.c

diff --git a/lib/openat-proc.c b/lib/openat-proc.c
index 5711896..2e2e966 100644 (file)
--- a/lib/openat-proc.c
+++ b/lib/openat-proc.c
@@ -80,6 +80,11 @@ openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file)
         proc_status = -1;
       else
         {
+          /* Detect whether /proc/self/fd/%i/../fd exists, where %i is the
+             number of a file descriptor open on /proc/self/fd.  On Linux,
+             that name resolves to /proc/self/fd, which was opened above.
+             However, on Solaris, it may resolve to /proc/self/fd/fd, which
+             cannot exist, since all names in /proc/self/fd are numeric.  */
           char dotdot_buf[PROC_SELF_FD_NAME_SIZE_BOUND (sizeof "../fd" - 1)];
           sprintf (dotdot_buf, PROC_SELF_FD_FORMAT, proc_self_fd, "../fd");
           proc_status = access (dotdot_buf, F_OK) ? -1 : 1;