texlive[45639] Build/source/texk/kpathsea: (do_subdir): arg cannot be

[commits+karl at tug.org]

Revision: 45639
          http://tug.org/svn/texlive?view=revision&revision=45639
Author:   karl
Date:     2017-10-29 22:53:23 +0100 (Sun, 29 Oct 2017)
Log Message:
-----------
(do_subdir): arg cannot be empty; make assert robust

Modified Paths:
--------------
    trunk/Build/source/texk/kpathsea/ChangeLog
    trunk/Build/source/texk/kpathsea/elt-dirs.c

Modified: trunk/Build/source/texk/kpathsea/ChangeLog
===================================================================
--- trunk/Build/source/texk/kpathsea/ChangeLog	2017-10-29 21:26:05 UTC (rev 45638)
+++ trunk/Build/source/texk/kpathsea/ChangeLog	2017-10-29 21:53:23 UTC (rev 45639)
@@ -1,3 +1,9 @@
+2017-10-29  Karl Berry  <karl at freefriends.org>
+
+	* elt-dirs.c (do_subdir): assert must include elt_length>0
+	to guarantee the assert of elt[elt_length-1] is valid.
+        From Doug McKenna, personal mail, 29oct17.
+
 2017-10-25  Karl Berry  <karl at tug.org>
 
 	* expand.c (brace_expand): do not look past the terminating

Modified: trunk/Build/source/texk/kpathsea/elt-dirs.c
===================================================================
--- trunk/Build/source/texk/kpathsea/elt-dirs.c	2017-10-29 21:26:05 UTC (rev 45638)
+++ trunk/Build/source/texk/kpathsea/elt-dirs.c	2017-10-29 21:53:23 UTC (rev 45639)
@@ -1,6 +1,7 @@
 /* elt-dirs.c: Translate a path element to its corresponding director{y,ies}.
 
-   Copyright 1993, 1994, 1995, 1996, 1997, 2008, 2009, 2010, 2011, 2016 Karl Berry.
+   Copyright 1993, 1994, 1995, 1996, 1997, 2008, 2009, 2010, 2011, 2016,
+   2017 Karl Berry.
    Copyright 1997, 1998, 1999, 2000, 2005 Olaf Weber.
 
    This library is free software; you can redistribute it and/or
@@ -100,7 +101,7 @@
 /* POST is a pointer into the original element (which may no longer be
    ELT) to just after the doubled DIR_SEP, perhaps to the null.  Append
    subdirectories of ELT (up to ELT_LENGTH, which must be a /) to
-   STR_LIST_PTR.  */
+   STR_LIST_PTR.  ELT must not be the empty string (or NULL).  */
 
 #ifdef WIN32
 /* Shared across recursive calls, it acts like a stack. */
@@ -127,8 +128,9 @@
   /* Some old compilers don't allow aggregate initialization.  */
   name = fn_copy0 (elt, elt_length);
 
-  assert (IS_DIR_SEP_CH (elt[elt_length - 1])
-          || IS_DEVICE_SEP (elt[elt_length - 1]));
+  assert (elt_length > 0
+          && (IS_DIR_SEP_CH (elt[elt_length - 1])
+              || IS_DEVICE_SEP (elt[elt_length - 1])));
 
 #if defined (WIN32)
   strcpy(dirname, FN_STRING(name));