fix(git): don't push an unborn HEAD from mkrep's default remote templates

mkrep only ever runs git init, never a commit, so a freshly created
repo has no HEAD yet. The gitea/gitlab default templates chained
`git push -u origin HEAD` unconditionally after linking the remote,
which fails immediately regardless of the remote ("src refspec HEAD
does not match any") -- reproduced by a real user hitting it on the
first mkrep --server call. Guard the push on HEAD actually resolving
to a commit; skipping it is the correct outcome (nothing to push yet),
and a real push failure once a commit exists still propagates.

functions/_mkrep_default_remote_cmd.fish

@@ -7,7 +7,12 @@
 # DESCRIPTION
 #   Prints the default remote-create command template for <type>, used by
 #   mkrep's --server flow when $MKREP_REMOTE_CMD is unset. Same {name},
-#   {user}, {server} placeholders as --new-remote.
+#   {user}, {server} placeholders as --new-remote. gitlab/gitea guard
+#   their final push on HEAD actually resolving to a commit -- mkrep only
+#   ever runs `git init`, so a fresh call has no commit yet, and
+#   `git push -u origin HEAD` errors on an unborn HEAD regardless of the
+#   remote. Skipping the push there is silent success, not a swallowed
+#   failure: once a commit exists, a real push failure still propagates.
 #
 # ARGUMENTS
 #   type   gitea, gitlab, or github
@@ -23,9 +28,9 @@ function _mkrep_default_remote_cmd --argument-names type
         case github
             echo 'gh repo create {name} --private --source=. --remote=origin --push'
         case gitlab
-            echo 'glab repo create {name} --private --skipGitInit && git remote add origin {server}/{user}/{name}.git && git push -u origin HEAD'
+            echo 'glab repo create {name} --private --skipGitInit && git remote add origin {server}/{user}/{name}.git && if git rev-parse --verify -q HEAD >/dev/null 2>&1; git push -u origin HEAD; end'
         case gitea
-            echo 'tea repos create --name {name} --private && git remote add origin {server}/{user}/{name}.git && git push -u origin HEAD'
+            echo 'tea repos create --name {name} --private && git remote add origin {server}/{user}/{name}.git && if git rev-parse --verify -q HEAD >/dev/null 2>&1; git push -u origin HEAD; end'
         case '*'
             return 1
     end

functions/mkrep.fish

@@ -104,14 +104,17 @@
 #
 #   Starting points for $MKREP_REMOTE_CMD, one per host CLI -- each assumes
 #   that tool is already installed and authenticated, creates a private
-#   repo under the caller's own account, and pushes the initial commit.
-#   These are also mkrep's built-in defaults for --server/$GIT_SERVER when
-#   $MKREP_REMOTE_CMD is unset. gh supports a one-shot
-#   --source/--remote/--push; glab and tea's create commands do not, so
-#   they are chained with the git commands that do the linking:
+#   repo under the caller's own account, and pushes it if there is
+#   already a commit to push (mkrep itself only runs git init, so a
+#   freshly created repo has none yet -- pushing an unborn HEAD is a
+#   guaranteed error regardless of the remote, so the push is skipped
+#   rather than attempted). These are also mkrep's built-in defaults for
+#   --server/$GIT_SERVER when $MKREP_REMOTE_CMD is unset. gh supports a
+#   one-shot --source/--remote/--push; glab and tea's create commands do
+#   not, so they are chained with the git commands that do the linking:
 #     GitHub (gh):   gh repo create {name} --private --source=. --remote=origin --push
-#     GitLab (glab): glab repo create {name} --private --skipGitInit && git remote add origin {server}/{user}/{name}.git && git push -u origin HEAD
-#     Gitea (tea):   tea repos create --name {name} --private && git remote add origin {server}/{user}/{name}.git && git push -u origin HEAD
+#     GitLab (glab): glab repo create {name} --private --skipGitInit && git remote add origin {server}/{user}/{name}.git && if git rev-parse --verify -q HEAD >/dev/null 2>&1; git push -u origin HEAD; end
+#     Gitea (tea):   tea repos create --name {name} --private && git remote add origin {server}/{user}/{name}.git && if git rev-parse --verify -q HEAD >/dev/null 2>&1; git push -u origin HEAD; end
 function mkrep --description 'Create a directory, cd into it, and git init it'
     __fish_palette
 

tests/test-mkrep.fish

@@ -255,6 +255,28 @@ function _mkrep_stub_tool --argument-names name exit_code
     chmod +x $stub_bin/$name
 end
 
+section "mkrep: --server's default gitea template survives an empty (commit-less) repo"
+
+begin
+    # Regression: mkrep only ever runs `git init`, so a freshly created
+    # repo has no commits yet. The default template's final push must not
+    # error on that unborn HEAD once `tea repos create` and `git remote
+    # add` (both real, local-only) have already succeeded.
+    printf '#!/bin/sh\ncase "$2" in\n  create) exit 0 ;;\n  *) exit 1 ;;\nesac\n' >$stub_bin/tea
+    chmod +x $stub_bin/tea
+    set -l base (_mkrep_sandbox)
+    set -l target $base/repo
+    set -lx PATH $stub_bin $PATH
+    set -lx GITEA_URL https://gitea.example.invalid
+    set -lx MKREP_REMOTE_CMD ''
+    mkrep --server gitea $target >/dev/null
+    check "default template exits 0 with no commits yet" 0 $status
+    set -l url (git -C $target remote get-url origin)
+    check "default template still linked the new remote" "https://gitea.example.invalid/$USER/repo.git" $url
+    cd $start
+    rm -rf $base
+end
+
 section "mkrep: --server auto-creates when the repo does not exist"
 
 begin