[glib] Use system PCRE unless --with-pcre=internal is given

[Simon McVittie <smcv src gnome org>]

commit 82c2461e3d719dfe11361c07502d1cf8a998c121
Author: Simon McVittie <simon mcvittie collabora co uk>
Date:   Tue Jan 5 12:20:20 2016 +0000

    Use system PCRE unless --with-pcre=internal is given
    
    Bug: https://bugzilla.gnome.org/show_bug.cgi?id=740573
    Reviewed-by: Emmanuele Bassi <ebassi gnome org>
    Signed-off-by: Simon McVittie <simon mcvittie collabora co uk>

 NEWS         |    7 +++++++
 README.in    |    7 +++++++
 configure.ac |    4 +++-
 3 files changed, 17 insertions(+), 1 deletions(-)
---
diff --git a/NEWS b/NEWS
index d90f2aa..33784f2 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,10 @@
+Overview of changes in GLib 2.47.5
+==================================
+
+* The system copy of PCRE is now used by default to implement GRegex.
+  Configure with --with-pcre=internal if a system PCRE version
+  is unavailable or undesired.
+
 Overview of changes in GLib 2.47.4
 ==================================
 
diff --git a/README.in b/README.in
index c2841a5..3e8b2e5 100644
--- a/README.in
+++ b/README.in
@@ -67,6 +67,13 @@ and attach the patch to that bug report.
 
 Patches should be in unified diff form. (The -up option to GNU diff.)
 
+Notes about GLib 2.48
+=====================
+
+* The system copy of PCRE is now used by default to implement GRegex.
+  Configure with --with-pcre=internal if a system PCRE version
+  is unavailable or undesired.
+
 Notes about GLib 2.46
 =====================
 
diff --git a/configure.ac b/configure.ac
index b9fb0e9..b62a4e2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2312,7 +2312,9 @@ PCRE_REQUIRED_VERSION=8.13
 # Check if we should use the internal or the system-supplied pcre
 AC_ARG_WITH(pcre,
             [AS_HELP_STRING([--with-pcre=@<:@internal/system@:>@],
-                            [whether to use system PCRE [default=internal]])])
+                            [whether to use system PCRE [default=system]])],
+            [],
+            [with_pcre=system])
 
 AM_CONDITIONAL(USE_SYSTEM_PCRE, [test "x$with_pcre" = xsystem])