d/merge-snapshot: extract major version & add a comment

2 files changed, 19 insertions, 1 deletions

diff --git a/debian/changelog b/debian/changelog
index d34fe34ff79..e30414a1f38 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+emacs-snapshot (29.1~git20220912.2) UNRELEASED; urgency=medium
+
+  * d/merge-snapshot: Extract major version number from configure.ac.
+  * d/merge-snapshot: Add comment explaining why we use 29.1 not 29.0.50.
+
+ -- Sean Whitton <spwhitton@spwhitton.name>  Sun, 16 Oct 2022 16:12:58 -0700
+
 emacs-snapshot (29.1~git20220912.1) unstable; urgency=medium
 
   * Package git snapshot.
diff --git a/debian/merge-snapshot b/debian/merge-snapshot
index fe003515ebd..8ee28d69a05 100755
--- a/debian/merge-snapshot
+++ b/debian/merge-snapshot
@@ -5,6 +5,7 @@ use strict;
 use warnings;
 
 use Cwd;
+use File::Spec::Functions "catfile";
 use Git::Wrapper;
 
 my $git = Git::Wrapper->new(getcwd);
@@ -24,6 +25,14 @@ $new_date =~ /\A([0-9]{4})-([0-9]{2})-([0-9]{2})/
 $new_date = $1 . $2 . $3;
 my $new_rev = $prev_date eq $new_date ? $prev_rev + 1 : 1;
 
+my $major_version;
+open my $fh, "<", catfile $git->dir, "configure.ac";
+for (<$fh>) {
+    $major_version = $1, last
+      if /AC_INIT\(\[GNU Emacs\], \[([0-9]+)\.0\.50\],/
+}
+$major_version or die "couldn't extract devel major version number";
+
 $git->merge({
         message =>
           "Merge remote-tracking branch 'origin/master' into athena/unstable"
@@ -31,7 +40,9 @@ $git->merge({
     $to_merge
 );
 
-system "dch", "-v29.1~git${new_date}.${new_rev}",
+# We use .1 not .0.50 because that's what's conventional
+# with Debian "~gitYYYYMMDD.N" git snapshot version numbers.
+system "dch", "-v${major_version}.1~git${new_date}.${new_rev}",
   $prev_distn eq "UNRELEASED" ? "" : "Package git snapshot.";
 $git->add("debian/changelog");
 $git->commit({ message => "changelog" });