Added support for checking out tags from git

src/rebar_deps.erl

@@ -269,10 +269,16 @@ download_source(AppDir, {hg, Url, Rev}) ->
     ok = filelib:ensure_dir(AppDir),
     rebar_utils:sh(?FMT("hg clone -U ~s ~s", [Url, filename:basename(AppDir)]), [], filename:dirname(AppDir)),
     rebar_utils:sh(?FMT("hg update ~s", [Rev]), [], AppDir);
-download_source(AppDir, {git, Url, Rev}) ->
+download_source(AppDir, {git, Url, {branch, Branch}}) ->
+    ok = filelib:ensure_dir(AppDir),
+    rebar_utils:sh(?FMT("git clone -n ~s ~s", [Url, filename:basename(AppDir)]), [], filename:dirname(AppDir)),
+    rebar_utils:sh(?FMT("git checkout ~s", [Branch]), [], AppDir);
+download_source(AppDir, {git, Url, {tag, Tag}}) ->
     ok = filelib:ensure_dir(AppDir),
     rebar_utils:sh(?FMT("git clone -n ~s ~s", [Url, filename:basename(AppDir)]), [], filename:dirname(AppDir)),
-    rebar_utils:sh(?FMT("git checkout ~s", [Rev]), [], AppDir);
+    rebar_utils:sh(?FMT("git checkout -b ~s", [Tag]), [], AppDir);
+download_source(AppDir, {git, Url, Rev}) ->
+    download_source(AppDir, {git, Url, {branch, Rev}});
 download_source(AppDir, {bzr, Url, Rev}) ->
     ok = filelib:ensure_dir(AppDir),
     rebar_utils:sh(?FMT("bzr branch -r ~s ~s ~s",