[PATCH 2/2] build: work around glibc and libsigsegv bugs

[Eric Blake]

* gnulib: Update to latest.
* m4/gnulib-cache.m4: Regenerate.
* docs/m4.texinfo (Index macro): Expose strstr bug.
* NEWS: Mention fixes.

Signed-off-by: Eric Blake <address@hidden>
---

Most gnulib fixes only affect systems outside the GNU/Linux domain,
but the gnulib fixes for strstr() in glibc, and for libsigsegv 2.8
being broken on Linux PowerPC64, are mainstream enough to warrant a
new m4 release in the near future.

 ChangeLog          |    6 ++++++
 NEWS               |    8 +++++++-
 doc/m4.texinfo     |   11 +++++++++++
 gnulib             |    2 +-
 m4/gnulib-cache.m4 |    4 ++--
 5 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 97f5f06..30c7821 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2010-10-21  Eric Blake  <address@hidden>

+       build: work around glibc and libsigsegv bugs
+       * gnulib: Update to latest.
+       * m4/gnulib-cache.m4: Regenerate.
+       * docs/m4.texinfo (Index macro): Expose strstr bug.
+       * NEWS: Mention fixes.
+
        docs: mention more history
        * doc/m4.texinfo (History): Add upcoming 1.4.16 release.

diff --git a/NEWS b/NEWS
index b713552..7cb962d 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,12 @@
 GNU M4 NEWS - User visible changes.

-* Noteworthy changes in release ?.? (????-??-??) [?]
+* Noteworthy changes in release 1.4.16 (2010-??-??) [?]
+
+** Ensure the `index' builtin cannot give false positive results.  On
+   glibc platforms, this avoids a strstr bug in glibc 2.9 through 2.12;
+   on many other platforms, it fixes a regression introduced in 1.4.11.
+
+** A number of portability improvements inherited from gnulib.


 * Noteworthy changes in release 1.4.15 (2010-08-31) [stable]
diff --git a/doc/m4.texinfo b/doc/m4.texinfo
index b66adbe..5ea6ff9 100644
--- a/doc/m4.texinfo
+++ b/doc/m4.texinfo
@@ -5642,6 +5642,17 @@ Index macro
 @result{}1
 @end example

address@hidden
address@hidden Expose a bug in the strstr() algorithm present in glibc
address@hidden 2.9 through 2.12 and in gnulib up to Sep 2010.
+
address@hidden
+index(`;:11-:12-:12-:12-:12-:12-:12-:12-:12.:12.:12.:12.:12.:12.:12.:12.:12-',
+`:12-:12-:12-:12-:12-:12-:12-:12-')
address@hidden
address@hidden example
address@hidden ignore
+
 @node Regexp
 @section Searching for regular expressions

diff --git a/gnulib b/gnulib
index c0ebdfe..b86f488 160000
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit c0ebdfe226c38c72db7c1944113fd19ff534e362
+Subproject commit b86f488e783121f54dbd44e17741fa3b29e9be9b
diff --git a/m4/gnulib-cache.m4 b/m4/gnulib-cache.m4
index 103bc16..ba783c3 100644
--- a/m4/gnulib-cache.m4
+++ b/m4/gnulib-cache.m4
@@ -10,8 +10,8 @@
 #
 # This file represents the specification of how gnulib-tool is used.
 # It acts as a cache: It is written and read by gnulib-tool.
-# In projects using CVS, this file is meant to be stored in CVS,
-# like the configure.ac and various Makefile.am files.
+# In projects that use version control, this file is meant to be put under
+# version control, like the configure.ac and various Makefile.am files.


 # Specification in the form of a command-line invocation:
-- 
1.7.2.3