[Libguestfs] [PATCH] build: mandate Jansson >= 2.7

[Pino Toscano]

Since we use APIs added in Jansson 2.7 (e.g. json_string_length), then
raise the minimum version required to that version.

Fixes commit bd1c5c9f4dcf38458099db8a0bf4659a07ef055d.
---
 docs/guestfs-building.pod | 2 +-
 m4/guestfs-libraries.m4   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/guestfs-building.pod b/docs/guestfs-building.pod
index bf80984e4..db429f1a9 100644
--- a/docs/guestfs-building.pod
+++ b/docs/guestfs-building.pod
@@ -169,7 +169,7 @@ I<Required>.
 
 I<Required>.
 
-=item Jansson
+=item Jansson E<ge> 2.7
 
 I<Required>.
 
diff --git a/m4/guestfs-libraries.m4 b/m4/guestfs-libraries.m4
index 67a0b7148..6d5f3e3c1 100644
--- a/m4/guestfs-libraries.m4
+++ b/m4/guestfs-libraries.m4
@@ -285,7 +285,7 @@ AC_CHECK_FUNCS([xmlBufferDetach])
 LIBS="$old_LIBS"
 
 dnl Check for Jansson JSON library (required).
-PKG_CHECK_MODULES([JANSSON], [jansson])
+PKG_CHECK_MODULES([JANSSON], [jansson >= 2.7])
 
 dnl Check for C++ (optional, we just use this to test the header works).
 AC_PROG_CXX
-- 
2.14.3