From e17980b7bc91eb74d2cccfcc4dc89e4dcead5609 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Wed, 16 Jul 2025 12:26:29 +0100
Subject: [PATCH] lib: New API: nbd_get_version_extra

This new API gets the ./configure --with-extra="..." string, usually
the empty string (for upstream builds) or the package NVR (for
downstream builds).

This commit also adds a test.

(cherry picked from commit 0b7e0831912c9efcd601b4738756a0aeb948df79)
---
 generator/API.ml    | 26 ++++++++++++++++++++++++--
 lib/handle.c        |  6 ++++++
 tests/get-version.c |  7 +++++++
 3 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/generator/API.ml b/generator/API.ml
index 8ee1843a..b1932dfa 100644
--- a/generator/API.ml
+++ b/generator/API.ml
@@ -4172,7 +4172,7 @@ versions.";
     longdesc = "\
 Returns the name of the library, always C<\"libnbd\"> unless
 the library was modified with another name at compile time.";
-    see_also = [Link "get_version"];
+    see_also = [Link "get_version"; Link "get_version_extra"];
   };
 
   "get_version", {
@@ -4220,7 +4220,26 @@ The release number is incremented for each release along a particular
 branch.
 
 =back";
-    see_also = [Link "get_package_name"];
+    see_also = [Link "get_package_name"; Link "get_version_extra"];
+  };
+
+  "get_version_extra", {
+    default_call with
+    args = []; ret = RStaticString; is_locked = false; may_set_error = false;
+    shortdesc = "return the extra version of the library";
+    longdesc = "\
+Return the extra version of libnbd.  This is a freeform string
+which is set at package build time using:
+
+ ./configure --with-extra=\"...\"
+
+and it intended to be used by downstream packagers (eg. Linux distributions)
+to convey extra version information, such as the precise version of
+the libnbd RPM, C<.deb> etc.
+
+The string may be C<\"\">, indicating that no extra version information
+is available, or that this is an upstream build of libnbd.";
+    see_also = [Link "get_package_name"; Link "get_version_extra"];
   };
 
   "kill_subprocess", {
@@ -4515,6 +4534,9 @@ let first_version = [
   "is_uri", (1, 22);
   "get_subprocess_pid", (1, 22);
 
+  (* Added in 1.23.x development cycle, will be stable and supported in 1.24 *)
+  "get_version_extra", (1, 24);
+
   (* These calls are proposed for a future version of libnbd, but
    * have not been added to any released version so far.
   "get_tls_certificates", (1, ??);
diff --git a/lib/handle.c b/lib/handle.c
index a263cc4c..ec64d601 100644
--- a/lib/handle.c
+++ b/lib/handle.c
@@ -566,6 +566,12 @@ nbd_unlocked_get_version (struct nbd_handle *h)
   return PACKAGE_VERSION;
 }
 
+const char *
+nbd_unlocked_get_version_extra (struct nbd_handle *h)
+{
+  return LIBNBD_VERSION_EXTRA;
+}
+
 int
 nbd_unlocked_kill_subprocess (struct nbd_handle *h, int signum)
 {
diff --git a/tests/get-version.c b/tests/get-version.c
index b8dc5338..c195e5f5 100644
--- a/tests/get-version.c
+++ b/tests/get-version.c
@@ -53,6 +53,13 @@ main (int argc, char *argv[])
   }
   assert (strcmp (s, PACKAGE_VERSION) == 0);
 
+  s = nbd_get_version_extra (nbd);
+  if (s == NULL) {
+    fprintf (stderr, "%s\n", nbd_get_error ());
+    exit (EXIT_FAILURE);
+  }
+  assert (strcmp (s, LIBNBD_VERSION_EXTRA) == 0);
+
   nbd_close (nbd);
   exit (EXIT_SUCCESS);
 }
-- 
2.47.3