Don't show new pr button when page is not compare pull

[yp05327]

Before:

After:

(TestOrg:test is a tag not branch)

Problem:
In the template, we will not add compare pull class when PageIsComparePull is false.

gitea/templates/repo/diff/compare.tmpl

Line 2 in a370efc

<div role="main" aria-label="{{.Title}}" class="page-content repository diff {{if .PageIsComparePull}}compare pull{{end}}">

But in the js, we are using .repository.compare.pull to find the button:

gitea/web_src/js/features/repo-legacy.js

Lines 552 to 563 in a370efc

	// Pull request
	const $repoComparePull = $('.repository.compare.pull');
	if ($repoComparePull.length > 0) {
	// show pull request form
	$repoComparePull.find('button.show-form').on('click', function (e) {
	e.preventDefault();
	hideElem($(this).parent());
	const $form = $repoComparePull.find('.pullrequest-form');
	showElem($form);
	});
	}

So, if PageIsComparePull is false, the New Pull Request button will be there, but has no response when we click it.

[silverwind]

Unrelated to this PR but I would ideally prefer if we eventually remove the need to click this button and just open directly into the PR form.

[a1012112796]

That's not a bug, empty pull request is a feature, which learned from gitlab, you can use this featue to create a coding plan with a new branch before add the code. first added in #12543.

[a1012112796]

example:

test version: 1.21.0+dev-437-gb9baed2c7, will check the master branch latest status later.

--- update :

looks ok also (version: Version: 1.21.0+dev-511-g88479e0df)：

[wxiaoguang]

Not a bug but a feature, need to write some comments for it.

[silverwind]

If empty PR is a feature, this change makes no sense. I'm sorry but I'll close it then.

[wxiaoguang]

If empty PR is a feature, this change makes no sense. I'm sorry but I'll close it then.

why not keep it open and write some comments?

[silverwind]

You mean make this PR comment-only?

[yp05327]

No, this is a bug, I know we can create empty pull request, but
when the base or the compare is a tag not branch, we should not display the new PR button
as I have mentioned in the discription

(TestOrg:test is a tag not branch)

So the root reason is that we forgot to check whether this is a tag selected in this compare page, not the problem of empty pull request.

You can confirm the difference in GitHub:
https://github.com/yp05327/test2/compare/main...testtag?expand=1
https://github.com/yp05327/test2/compare/main...testtagpr?expand=1

ps: I noticed this problem because I created a Release with 0 commits, something like this:

Then if you click 0 commits you will get this page:

[a1012112796]

Okay, I see it.

[a1012112796]

but looks it's not necessary to show this messsage also. because one of these is not a 'branch' ...

ref:

or maybe add a new help tips like "can't create pull request because the head or base ref is not a branch. "

[a1012112796]

so looks this option is better:

diff --git a/templates/repo/diff/compare.tmpl b/templates/repo/diff/compare.tmpl
index 3bb7c2e81..a63d4801d 100644
--- a/templates/repo/diff/compare.tmpl
+++ b/templates/repo/diff/compare.tmpl
@@ -176,7 +176,7 @@
 		</div>
 	</div>
 
-	{{if .IsNothingToCompare}}
+	{{if and .PageIsComparePull .IsNothingToCompare}}
 		{{if and $.IsSigned $.AllowEmptyPr (not .Repository.IsArchived)}}
 			<div class="ui segment">{{.locale.Tr "repo.pulls.nothing_to_compare_and_allow_empty_pr"}}</div>
 			<div class="ui info message show-form-container {{if .Flash}}gt-hidden{{end}}">
@@ -229,7 +229,7 @@
 			{{end}}
 			{{$showDiffBox = true}}
 		{{end}}
-	{{else}}
+	{{else if not .IsNothingToCompare}}
 		{{$showDiffBox = true}}
 	{{end}}
 	</div>

``

[silverwind]

Retracting review for now.

[yp05327]

so looks this option is better:

Done.

[lunny]

But we still need the comment that the two branches are equal.

[yp05327]

.PageIsComparePull is not just used in the case of tag selected.
We should use if and .HeadIsBranch .BaseIsBranch to check whether tag is selected.

[silverwind]

Can we remove the "New PR" button altogether and just show the form directly if applicable? I'm willing to collaborate on this here. It would be nice to have for #26743 because it's rather unintuitive when you F5 on the new PR page and it does not immediatly show the restored content.