bin/rebase: Add -b and -m options

The rebase command syntax has confused people a lot.  Let's follow
git here and add a `-b/--branch` option and encourage people to use
that.  The case of switching remotes is `-m/--remote`; it's definitely
unfortunate that `-r` is already taken for `--reboot`.

One thing I'm a little bit unhappy about is how we're doing logic
on the client side here.  Changing the DBus API for this would
also be awkward though.

Closes: https://github.com/projectatomic/rpm-ostree/issues/886

Closes: #890
Approved by: jlebon

man/rpm-ostree.xml

@@ -247,12 +247,24 @@ Boston, MA 02111-1307, USA.
           </para>
           <para>
             The full syntax is <literal>rebase REMOTENAME:BRANCHNAME</literal>.
-            Specifying just <literal>BRANCHNAME</literal> will reuse the same
-            remote. You may also omit one of <literal>REMOTENAME</literal> or
-            <literal>BRANCHNAME</literal> (keeping the colon). In the former
-            case, the branch refers to a local branch; in the latter case, the
-            same branch will be used on a different remote.
+            Alternatively, you can use the <command>--branch</command> or
+            <command>--remote</command> options mentioned below. With the
+            argument syntax, specifying just <literal>BRANCHNAME</literal> will
+            reuse the same remote. You may also omit one of
+            <literal>REMOTENAME</literal> or <literal>BRANCHNAME</literal>
+            (keeping the colon). In the former case, the branch refers to a
+            local branch; in the latter case, the same branch will be used on a
+            different remote.
           </para>
+          <para>
+            <command>--branch</command> or <command>-b</command> to
+            to pick a branch name.
+          </para>
+          <para>
+            <command>--remote</command> or <command>-m</command> to
+            to pick a remote name.
+          </para>
+
         </listitem>
       </varlistentry>
 

src/app/rpmostree-builtin-rebase.c

@@ -33,9 +33,13 @@
 static char *opt_osname;
 static gboolean opt_reboot;
 static gboolean opt_skip_purge;
+static char * opt_branch;
+static char * opt_remote;
 
 static GOptionEntry option_entries[] = {
   { "os", 0, 0, G_OPTION_ARG_STRING, &opt_osname, "Operate on provided OSNAME", "OSNAME" },
+  { "branch", 'b', 0, G_OPTION_ARG_STRING, &opt_branch, "Rebase to branch BRANCH; use --remote to change remote as well", "BRANCH" },
+  { "remote", 'm', 0, G_OPTION_ARG_STRING, &opt_remote, "Rebase to current branch name using REMOTE; may also be combined with --branch", "REMOTE" },
   { "reboot", 'r', 0, G_OPTION_ARG_NONE, &opt_reboot, "Initiate a reboot after rebase is finished", NULL },
   { "skip-purge", 0, 0, G_OPTION_ARG_NONE, &opt_skip_purge, "Keep previous refspec after rebase", NULL },
   { NULL }
@@ -49,6 +53,7 @@ rpmostree_builtin_rebase (int             argc,
                           GError        **error)
 {
   const char *new_provided_refspec;
+  g_autofree char *new_refspec_owned = NULL;
   const char *revision = NULL;
 
   /* forced blank for now */
@@ -74,21 +79,37 @@ rpmostree_builtin_rebase (int             argc,
                                        error))
     return EXIT_FAILURE;
 
-  if (argc < 2 || argc > 3)
+  if (argc > 3)
     {
-      rpmostree_usage_error (context, "Too few or too many arguments", error);
+      rpmostree_usage_error (context, "Too many arguments", error);
       return EXIT_FAILURE;
     }
 
-  new_provided_refspec = argv[1];
-
-  if (argc == 3)
-    revision = argv[2];
-
   if (!rpmostree_load_os_proxy (sysroot_proxy, opt_osname,
                                 cancellable, &os_proxy, error))
     return EXIT_FAILURE;
 
+  if (argc < 2 && !(opt_branch || opt_remote))
+    {
+      return rpmostree_usage_error (context, "Must specify refspec, or -b branch or -r remote", error), EXIT_FAILURE;
+    }
+  else if (argc >= 2)
+    {
+      new_provided_refspec = argv[1];
+      if (argc == 3)
+        revision = argv[2];
+    }
+  else
+    {
+      if (opt_remote)
+        {
+          new_provided_refspec = new_refspec_owned =
+            g_strconcat (opt_remote, ":", opt_branch ?: "", NULL);
+        }
+      else
+        new_provided_refspec = opt_branch;
+    }
+
   g_autoptr(GVariant) options =
     rpmostree_get_options_variant (opt_reboot,
                                    TRUE,   /* allow-downgrade */

tests/check/test-basic.sh

@@ -24,7 +24,7 @@ export RPMOSTREE_SUPPRESS_REQUIRES_ROOT_CHECK=yes
 
 ensure_dbus
 
-echo "1..23"
+echo "1..24"
 
 setup_os_repository "archive-z2" "syslinux"
 
@@ -157,6 +157,18 @@ rpm-ostree rebase --os=testos another-branch
 assert_status_jq '.deployments[0].origin == "another-branch"'
 echo "ok rebase from local branch to local branch"
 
+rpm-ostree rebase --skip-purge --os=testos testos:testos/buildmaster/x86_64-runtime
+assert_status_jq '.deployments[0].origin == "testos:testos/buildmaster/x86_64-runtime"'
+ostree --repo=${test_tmpdir}/testos-repo commit --add-metadata-string version=1.0.2 -b testos/stable/x86_64-runtime -s "Build" \
+       --tree=ref=testos/buildmaster/x86_64-runtime
+rpm-ostree rebase --skip-purge --os=testos -b testos/stable/x86_64-runtime
+assert_status_jq '.deployments[0].origin == "testos:testos/stable/x86_64-runtime"'
+ostree --repo=${test_tmpdir}/sysroot/ostree/repo commit -b localbranch --tree=ref=testos:testos/stable/x86_64-runtime
+rpm-ostree rebase --skip-purge --os=testos -m '' -b localbranch
+assert_status_jq '.deployments[0].origin == "localbranch"'
+echo "ok rebase new syntax"
+
+rpm-ostree rebase --os=testos :another-branch
 originpath=$(ostree admin --sysroot=sysroot --print-current-dir).origin
 echo "unconfigured-state=Access to TestOS requires ONE BILLION DOLLARS" >> ${originpath}
 rpm-ostree reload