From b300e3f48524cf16f3898cad6b843f52196a22a3 Mon Sep 17 00:00:00 2001
From: Lunny Xiao <xiaolunwen@gmail.com>
Date: Sat, 18 Dec 2021 06:20:27 +0800
Subject: [PATCH] Support open compare page directly (#17975)

* Support open compare page directly

* simple code

* Some improvements

Co-authored-by: 6543 <6543@obermui.de>
---
 routers/web/repo/compare.go | 26 ++++++++++++--------------
 routers/web/web.go          |  1 +
 2 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/routers/web/repo/compare.go b/routers/web/repo/compare.go
index 4f2d708079..30b1ca669e 100644
--- a/routers/web/repo/compare.go
+++ b/routers/web/repo/compare.go
@@ -215,23 +215,21 @@ func ParseCompareInfo(ctx *context.Context) *CompareInfo {
 	)
 
 	infoPath = ctx.Params("*")
-	infos := strings.SplitN(infoPath, "...", 2)
-
-	if len(infos) != 2 {
-		infos = []string{baseRepo.DefaultBranch, infoPath}
-		if strings.Contains(infoPath, "..") {
-			infos = strings.SplitN(infoPath, "..", 2)
-			ci.DirectComparison = true
-			ctx.Data["PageIsComparePull"] = false
+	var infos []string
+	if infoPath == "" {
+		infos = []string{baseRepo.DefaultBranch, baseRepo.DefaultBranch}
+	} else {
+		infos = strings.SplitN(infoPath, "...", 2)
+		if len(infos) != 2 {
+			if infos = strings.SplitN(infoPath, "..", 2); len(infos) == 2 {
+				ci.DirectComparison = true
+				ctx.Data["PageIsComparePull"] = false
+			} else {
+				infos = []string{baseRepo.DefaultBranch, infoPath}
+			}
 		}
 	}
 
-	if len(infos) != 2 {
-		log.Trace("ParseCompareInfo[%d]: not enough compared branches information %s", baseRepo.ID, infos)
-		ctx.NotFound("CompareAndPullRequest", nil)
-		return nil
-	}
-
 	ctx.Data["BaseName"] = baseRepo.OwnerName
 	ci.BaseBranch = infos[0]
 	ctx.Data["BaseBranch"] = ci.BaseBranch
diff --git a/routers/web/web.go b/routers/web/web.go
index 44ac751c31..6ede410e3e 100644
--- a/routers/web/web.go
+++ b/routers/web/web.go
@@ -702,6 +702,7 @@ func RegisterRoutes(m *web.Route) {
 		m.Group("/milestone", func() {
 			m.Get("/{id}", repo.MilestoneIssuesAndPulls)
 		}, reqRepoIssuesOrPullsReader, context.RepoRef())
+		m.Get("/compare", repo.MustBeNotEmpty, reqRepoCodeReader, repo.SetEditorconfigIfExists, ignSignIn, repo.SetDiffViewStyle, repo.SetWhitespaceBehavior, repo.CompareDiff)
 		m.Combo("/compare/*", repo.MustBeNotEmpty, reqRepoCodeReader, repo.SetEditorconfigIfExists).
 			Get(ignSignIn, repo.SetDiffViewStyle, repo.SetWhitespaceBehavior, repo.CompareDiff).
 			Post(reqSignIn, context.RepoMustNotBeArchived(), reqRepoPullsReader, repo.MustAllowPulls, bindIgnErr(forms.CreateIssueForm{}), repo.SetWhitespaceBehavior, repo.CompareAndPullRequestPost)