cli: add --allow-empty-description flag to push

This commit adds an optional flag to be able to push commits with an
empty description to a remote git repo. While the default behavior is
ideal we might need to interact with a repo that has an empty commit
description in it. I ran into this issue a few weeks ago pushing commits
from an open source repo to an empty repo and had to go back to using
git for that push as I would not want to rewrite the history which was
many many years long just for that.

This flag allows users an escape hatch for pushing empty descriptions
for commits and they're sure that they want that behavior.

This commit adds the flag to the `git push` command and updates the docs
for the command. It also updates the original test to make sure that the
flag works as intended to reject the commit when not set and to allow
the commit when the flag is set.

Closes martinvonz#2633

CHANGELOG.md

@@ -21,6 +21,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Conflict markers now include an explanation of what each part of the conflict
   represents.
 
+* `jj git push` now can push commits with empty descriptions with the
+  `--allow-empty-description` flag
+
 ### Fixed bugs
 
 ## [0.17.1] - 2024-05-07

cli/src/commands/git.rs

@@ -220,6 +220,9 @@ pub struct GitPushArgs {
     /// correspond to missing local branches.
     #[arg(long)]
     deleted: bool,
+    /// Allow pushing commits with empty descriptions
+    #[arg(long)]
+    allow_empty_description: bool,
     /// Push branches pointing to these commits (can be repeated)
     #[arg(long, short)]
     revisions: Vec<RevisionArg>,
@@ -930,7 +933,7 @@ fn cmd_git_push(
     {
         let commit = commit?;
         let mut reasons = vec![];
-        if commit.description().is_empty() {
+        if commit.description().is_empty() && !args.allow_empty_description {
             reasons.push("it has no description");
         }
         if commit.author().name.is_empty()

cli/tests/cli-reference@.md.snap

@@ -931,6 +931,10 @@ By default, pushes any branches pointing to `remote_branches(remote=<remote>)..@
 
   Possible values: `true`, `false`
 
+* `--allow-empty-description` — Allow pushing commits with empty descriptions
+
+  Possible values: `true`, `false`
+
 * `-r`, `--revisions <REVISIONS>` — Push branches pointing to these commits (can be repeated)
 * `-c`, `--change <CHANGE>` — Push this commit by creating a branch based on its change ID (can be repeated)
 * `--dry-run` — Only display what will change on the remote

cli/tests/test_git_push.rs

@@ -642,6 +642,16 @@ fn test_git_push_no_description() {
     insta::assert_snapshot!(stderr, @r###"
     Error: Won't push commit 5b36783cd11c since it has no description
     "###);
+    test_env.jj_cmd_ok(
+        &workspace_root,
+        &[
+            "git",
+            "push",
+            "--branch",
+            "my-branch",
+            "--allow-empty-description",
+        ],
+    );
 }
 
 #[test]