From: Paul Eggert <eggert@cs.ucla.edu>
Date: Thu, 5 Oct 2017 22:55:10 +0000 (-0700)
Subject: Fix bug with unmounted directory on GNU/Linux
X-Git-Tag: emacs-26.0.90~45^2~19
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=db893ab863770ef3f89102d6837cd3eb021429ba;p=emacs.git

Fix bug with unmounted directory on GNU/Linux

* src/sysdep.c (emacs_get_current_dir_name): Do not use
get_current_dir_name result unless it is absolute (Bug#27871).
---

diff --git a/src/sysdep.c b/src/sysdep.c
index 26d381f5796..8291a606bea 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -232,7 +232,18 @@ emacs_get_current_dir_name (void)
   bool use_libc = true;
 #  endif
   if (use_libc)
-    return get_current_dir_name ();
+    {
+      /* GNU/Linux get_current_dir_name can return a string starting
+	 with "(unreachable)" (Bug#27871).  */
+      char *wd = get_current_dir_name ();
+      if (wd && ! (IS_DIRECTORY_SEP (*wd) || (*wd && IS_DEVICE_SEP (wd[1]))))
+	{
+	  free (wd);
+	  errno = ENOENT;
+	  return NULL;
+	}
+      return wd;
+    }
 # endif
 
   char *buf;