Provide a GCRYPT_VERSION_NUMBER macro.

* src/gcrypt.h.in (GCRYPT_VERSION_NUMBER): New.
* configure.ac (VERSION_NUMBER): New ac_subst.
* compat/compat.c (_gcry_compat_identification): Include revision and
timestamp.
* src/global.c (_gcry_vcontrol): Move call to above function ...
(gcry_check_version): .. here.

4 files changed, 13 insertions, 2 deletions

diff --git a/compat/compat.c b/compat/compat.c
index e2a03933..3d979f89 100644
--- a/compat/compat.c
+++ b/compat/compat.c
@@ -30,6 +30,8 @@ _gcry_compat_identification (void)
     "This is Libgcrypt " PACKAGE_VERSION " - The GNU Crypto Library\n"
     "Copyright 2000, 2002, 2003, 2004, 2007, 2008, 2009,\n"
     "          2010, 2011 Free Software Foundation, Inc.\n"
+    "\n"
+    "(" BUILD_REVISION " " BUILD_TIMESTAMP ")\n"
     "\n\n";
   return blurb;
 }
diff --git a/configure.ac b/configure.ac
index 39eba129..83ba4860 100644
--- a/configure.ac
+++ b/configure.ac
@@ -127,6 +127,9 @@ AC_SUBST(PACKAGE)
 AC_SUBST(VERSION)
 AC_DEFINE_UNQUOTED(PACKAGE, "$PACKAGE", [Name of this package])
 AC_DEFINE_UNQUOTED(VERSION, "$VERSION", [Version of this package])
+VERSION_NUMBER=m4_esyscmd(printf "0x%02x%02x%02x" mym4_version_major \
+                          mym4_version_minor mym4_version_micro)
+AC_SUBST(VERSION_NUMBER)
 
 
 ######################
diff --git a/src/gcrypt.h.in b/src/gcrypt.h.in
index dab7033a..86faa2d7 100644
--- a/src/gcrypt.h.in
+++ b/src/gcrypt.h.in
@@ -63,6 +63,11 @@ extern "C" {
    matches the installed library.  */
 #define GCRYPT_VERSION "@VERSION@"
 
+/* The version number of this header.  It may be used to handle minor
+   API incompatibilities.  */
+#define GCRYPT_VERSION_NUMBER @VERSION_NUMBER@
+
+
 /* Internal: We can't use the convenience macros for the multi
    precision integer functions when building this library. */
 #ifdef _GCRYPT_IN_LIBGCRYPT
diff --git a/src/global.c b/src/global.c
index 24cfca51..9b9d531a 100644
--- a/src/global.c
+++ b/src/global.c
@@ -236,6 +236,9 @@ gcry_check_version( const char *req_version )
     int rq_major, rq_minor, rq_micro;
     const char *my_plvl;
 
+    if (req_version && req_version[0] == 1 && req_version[1] == 1)
+        return _gcry_compat_identification ();
+
     /* Initialize library.  */
     global_init ();
 
@@ -607,8 +610,6 @@ _gcry_vcontrol (enum gcry_ctl_cmds cmd, va_list arg_ptr)
       break;
 
     default:
-      /* A call to make sure that the dummy code is linked in.  */
-      _gcry_compat_identification ();
       err = GPG_ERR_INV_OP;
     }