builder-main: Set a default build subject and body

src/builder-main.c

@@ -1096,6 +1096,12 @@ main (int    argc,
       g_print ("Exporting %s to repo\n", builder_manifest_get_id (manifest));
       builder_set_term_title (_("Exporting to repository"));
 
+      if (opt_subject == NULL)
+        opt_subject = get_default_build_subject ();
+
+      if (opt_body == NULL)
+        opt_body = get_default_build_body (manifest_sha256);
+
       if (!do_export (build_context, &error,
                       FALSE,
                       flatpak_file_get_path_cached (export_repo),

src/builder-utils.c

@@ -1973,3 +1973,33 @@ appstream_has_version (int major,
          (as_major == major && as_minor > minor) ||
          (as_major == major && as_minor == minor && as_micro >= micro);
 }
+
+char *
+get_default_build_subject (void)
+{
+  g_auto(GStrv) parts = NULL;
+  g_autofree char *output = NULL;
+  const char *argv[] = { "git", "log", "-1",
+                         "--pretty=format:%s%x1f%h",
+                         "--abbrev=12", NULL };
+
+  if (!flatpak_spawnv (NULL, &output, G_SUBPROCESS_FLAGS_STDERR_SILENCE,
+                       NULL, argv, NULL))
+    return NULL;
+
+  parts = g_strsplit (output, "\x1f", 2);
+  if (parts[0] == NULL || parts[1] == NULL)
+    return NULL;
+
+  g_autofree char *tmp = parts[0];
+  parts[0] = g_str_to_ascii (tmp, NULL);
+  parts[0][MIN (strlen (parts[0]), 58)] = '\0';
+
+  return g_strdup_printf ("%s (%s)", parts[0], parts[1]);
+}
+
+char *
+get_default_build_body (const char *sha)
+{
+  return g_strdup_printf ("Manifest checksum: %s", sha);
+}

src/builder-utils.h

@@ -228,6 +228,9 @@ gboolean appstream_has_version (int major,
                                 int minor,
                                 int micro);
 
+char *get_default_build_subject (void);
+char *get_default_build_body (const char *sha);
+
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (FlatpakXml, flatpak_xml_free);
 
 G_END_DECLS

tests/meson.build

@@ -16,6 +16,7 @@ test_names = [
   'test-builder-cleanup',
   'test-builder-licence-paths',
   'test-builder-src-date-epoch',
+  'test-build-subj',
 ]
 
 tap_test = find_program(

tests/test-build-subj.sh

@@ -0,0 +1,127 @@
+#!/bin/bash
+#
+# Copyright (C) 2026 Boudhayan Bhattacharya <bbhtt@bbhtt.in>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the
+# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+set -euo pipefail
+
+. $(dirname $0)/libtest.sh
+
+skip_without_fuse
+
+echo "1..3"
+
+setup_repo
+install_repo
+setup_sdk_repo
+install_sdk_repo
+
+# Flatpak only exposes subject but not body
+#
+# ostree show format:
+#
+# commit 5f7703dc87237cfd81ace54e660cc4308c63e0ff59e546332202d0743a0c2f93
+# ContentChecksum: c283ccf614d1e5a07b2e9cb4e3eae3ff5373d1cad8a377b7d8fa553271ac2440
+# Date: 2026-05-28 05:50:51 +0000
+#
+#     A subject
+#
+#     A body
+#
+
+ostree_get_subject () {
+    local repo=$1
+    local ref=$2
+    ostree show --repo="$repo" "$ref" | awk '/^$/{found=1; next} found{sub(/^    /, ""); print; exit}'
+}
+
+ostree_get_body () {
+    local repo=$1
+    local ref=$2
+    ostree show --repo="$repo" "$ref" | awk '/^$/{found=1; next} found{sub(/^    /, ""); print}' | tail -n +2
+}
+
+TEST_GIT_DIR="$(mktemp -d)"
+
+cd "$TEST_GIT_DIR"
+
+git init -q
+git config --local user.email "test@flatpak.org"
+git config --local user.name "test"
+git commit -q --allow-empty -m "Init"
+
+APP_ID="org.test.git_subj"
+MANIFEST_NAME="$APP_ID.json"
+REPO="$TEST_DATA_DIR/repo"
+COMMIT_SUBJ="Add manifést foo bar foo bar foo bar foo bar foo bar foo bar foo bar foo bar foo bar"
+
+cat > "$MANIFEST_NAME" <<'EOF'
+{
+    "app-id": "org.test.git_subj",
+    "runtime": "org.test.Platform",
+    "sdk": "org.test.Sdk",
+    "modules": [{
+        "name": "test",
+        "buildsystem": "simple",
+        "build-commands": ["mkdir -p /app"]
+    }]
+}
+EOF
+
+git add "$MANIFEST_NAME"
+git commit -q -m "$COMMIT_SUBJ"
+
+COMMIT_HASH="$(git rev-parse --short=12 HEAD)"
+MANIFEST_SHA256="$(sha256sum "$MANIFEST_NAME" | awk '{print $1}')"
+EXPECTED_SUBJECT="Add manifest foo bar foo bar foo bar foo bar foo bar foo b ($COMMIT_HASH)"
+EXPECTED_BODY="Manifest checksum: $MANIFEST_SHA256"
+
+${FLATPAK_BUILDER} --force-clean --repo="$REPO"_1 appdir "$MANIFEST_NAME" >&2
+
+REF="$(ostree refs --repo="$REPO"_1 | grep "^app/$APP_ID")"
+SUBJECT="$(ostree_get_subject "$REPO"_1 "$REF")"
+BODY="$(ostree_get_body "$REPO"_1 "$REF")"
+
+assert_streq "$SUBJECT" "$EXPECTED_SUBJECT"
+assert_streq "$BODY" "$EXPECTED_BODY"
+
+echo "ok default subject and body are set from git"
+
+${FLATPAK_BUILDER} --force-clean --repo="$REPO"_2 \
+    --subject="Custom subject" --body="Custom body" appdir "$MANIFEST_NAME" >&2
+
+REF="$(ostree refs --repo="$REPO"_2 | grep "^app/$APP_ID")"
+SUBJECT="$(ostree_get_subject "$REPO"_2 "$REF")"
+BODY="$(ostree_get_body "$REPO"_2 "$REF")"
+
+assert_streq "$SUBJECT" "Custom subject"
+assert_streq "$BODY" "Custom body"
+
+echo "ok explicit subject and body override defaults"
+
+rm -rf "$TEST_GIT_DIR/.git"
+
+${FLATPAK_BUILDER} --force-clean --repo="$REPO"_3 appdir "$MANIFEST_NAME" >&2
+
+REF="$(ostree refs --repo="$REPO"_3 | grep "^app/$APP_ID")"
+SUBJECT="$(ostree_get_subject "$REPO"_3 "$REF")"
+BODY="$(ostree_get_body "$REPO"_3 "$REF")"
+
+assert_streq "$SUBJECT" "Export $APP_ID"
+assert_streq "$BODY" "$EXPECTED_BODY"
+
+echo "ok default export subject is used outside git dir"