Handle missing default branch better in owner/repo/branches page (#18290)

This PR more nicely handles a missing default branch in owner/repo/branches

Fix #18265

Signed-off-by: Andrew Thornton <art27@cantab.net>

2 files changed, 65 insertions, 54 deletions

diff --git a/routers/web/repo/branch.go b/routers/web/repo/branch.go
index 9247202086..29b8acd61c 100644
--- a/routers/web/repo/branch.go
+++ b/routers/web/repo/branch.go
@@ -72,11 +72,12 @@ func Branches(ctx *context.Context) {
 
 	skip := (page - 1) * limit
 	log.Debug("Branches: skip: %d limit: %d", skip, limit)
-	branches, branchesCount := loadBranches(ctx, skip, limit)
+	defaultBranchBranch, branches, branchesCount := loadBranches(ctx, skip, limit)
 	if ctx.Written() {
 		return
 	}
 	ctx.Data["Branches"] = branches
+	ctx.Data["DefaultBranchBranch"] = defaultBranchBranch
 	pager := context.NewPagination(int(branchesCount), setting.Git.BranchesRangeSize, page, 5)
 	pager.SetDefaultParams(ctx)
 	ctx.Data["Page"] = pager
@@ -165,25 +166,28 @@ func redirect(ctx *context.Context) {
 
 // loadBranches loads branches from the repository limited by page & pageSize.
 // NOTE: May write to context on error.
-func loadBranches(ctx *context.Context, skip, limit int) ([]*Branch, int) {
+func loadBranches(ctx *context.Context, skip, limit int) (*Branch, []*Branch, int) {
 	defaultBranch, err := ctx.Repo.GitRepo.GetBranch(ctx.Repo.Repository.DefaultBranch)
 	if err != nil {
-		log.Error("loadBranches: get default branch: %v", err)
-		ctx.ServerError("GetDefaultBranch", err)
-		return nil, 0
+		if !git.IsErrBranchNotExist(err) {
+			log.Error("loadBranches: get default branch: %v", err)
+			ctx.ServerError("GetDefaultBranch", err)
+			return nil, nil, 0
+		}
+		log.Warn("loadBranches: missing default branch %s for %-v", ctx.Repo.Repository.DefaultBranch, ctx.Repo.Repository)
 	}
 
 	rawBranches, totalNumOfBranches, err := ctx.Repo.GitRepo.GetBranches(skip, limit)
 	if err != nil {
 		log.Error("GetBranches: %v", err)
 		ctx.ServerError("GetBranches", err)
-		return nil, 0
+		return nil, nil, 0
 	}
 
 	protectedBranches, err := models.GetProtectedBranches(ctx.Repo.Repository.ID)
 	if err != nil {
 		ctx.ServerError("GetProtectedBranches", err)
-		return nil, 0
+		return nil, nil, 0
 	}
 
 	repoIDToRepo := map[int64]*repo_model.Repository{}
@@ -194,36 +198,40 @@ func loadBranches(ctx *context.Context, skip, limit int) ([]*Branch, int) {
 
 	var branches []*Branch
 	for i := range rawBranches {
-		if rawBranches[i].Name == defaultBranch.Name {
+		if defaultBranch != nil && rawBranches[i].Name == defaultBranch.Name {
 			// Skip default branch
 			continue
 		}
 
-		var branch = loadOneBranch(ctx, rawBranches[i], protectedBranches, repoIDToRepo, repoIDToGitRepo)
+		var branch = loadOneBranch(ctx, rawBranches[i], defaultBranch, protectedBranches, repoIDToRepo, repoIDToGitRepo)
 		if branch == nil {
-			return nil, 0
+			return nil, nil, 0
 		}
 
 		branches = append(branches, branch)
 	}
 
-	// Always add the default branch
-	log.Debug("loadOneBranch: load default: '%s'", defaultBranch.Name)
-	branches = append(branches, loadOneBranch(ctx, defaultBranch, protectedBranches, repoIDToRepo, repoIDToGitRepo))
+	var defaultBranchBranch *Branch
+	if defaultBranch != nil {
+		// Always add the default branch
+		log.Debug("loadOneBranch: load default: '%s'", defaultBranch.Name)
+		defaultBranchBranch = loadOneBranch(ctx, defaultBranch, defaultBranch, protectedBranches, repoIDToRepo, repoIDToGitRepo)
+		branches = append(branches, defaultBranchBranch)
+	}
 
 	if ctx.Repo.CanWrite(unit.TypeCode) {
 		deletedBranches, err := getDeletedBranches(ctx)
 		if err != nil {
 			ctx.ServerError("getDeletedBranches", err)
-			return nil, 0
+			return nil, nil, 0
 		}
 		branches = append(branches, deletedBranches...)
 	}
 
-	return branches, totalNumOfBranches
+	return defaultBranchBranch, branches, totalNumOfBranches
 }
 
-func loadOneBranch(ctx *context.Context, rawBranch *git.Branch, protectedBranches []*models.ProtectedBranch,
+func loadOneBranch(ctx *context.Context, rawBranch, defaultBranch *git.Branch, protectedBranches []*models.ProtectedBranch,
 	repoIDToRepo map[int64]*repo_model.Repository,
 	repoIDToGitRepo map[int64]*git.Repository) *Branch {
 	log.Trace("loadOneBranch: '%s'", rawBranch.Name)
@@ -243,10 +251,15 @@ func loadOneBranch(ctx *context.Context, rawBranch *git.Branch, protectedBranche
 		}
 	}
 
-	divergence, divergenceError := files_service.CountDivergingCommits(ctx.Repo.Repository, git.BranchPrefix+branchName)
-	if divergenceError != nil {
-		ctx.ServerError("CountDivergingCommits", divergenceError)
-		return nil
+	divergence := &git.DivergeObject{
+		Ahead:  -1,
+		Behind: -1,
+	}
+	if defaultBranch != nil {
+		divergence, err = files_service.CountDivergingCommits(ctx.Repo.Repository, git.BranchPrefix+branchName)
+		if err != nil {
+			log.Error("CountDivergingCommits", err)
+		}
 	}
 
 	pr, err := models.GetLatestPullRequestByHeadInfo(ctx.Repo.Repository.ID, branchName)
diff --git a/templates/repo/branch/list.tmpl b/templates/repo/branch/list.tmpl
index 3580808aac..fc81901069 100644
--- a/templates/repo/branch/list.tmpl
+++ b/templates/repo/branch/list.tmpl
@@ -4,43 +4,41 @@
 	<div class="ui container">
 		{{template "base/alert" .}}
 		{{template "repo/sub_menu" .}}
-		<h4 class="ui top attached header">
-			{{.i18n.Tr "repo.default_branch"}}
-		</h4>
+		{{if .DefaultBranchBranch}}
+			<h4 class="ui top attached header">
+				{{.i18n.Tr "repo.default_branch"}}
+			</h4>
 
-		<div class="ui attached table segment">
-			<table class="ui very basic striped fixed table single line">
-				<tbody>
-					<tr>
-						<td>
-						{{range .Branches}}
-							{{if eq .Name $.DefaultBranch}}
-								{{if .IsProtected}}
+			<div class="ui attached table segment">
+				<table class="ui very basic striped fixed table single line">
+					<tbody>
+						<tr>
+							<td>
+								{{if .DefaultBranchBranch.IsProtected}}
 									{{svg "octicon-shield-lock"}}
 								{{end}}
-								<a href="{{$.RepoLink}}/src/branch/{{PathEscapeSegments $.DefaultBranch}}">{{$.DefaultBranch}}</a>
-								<p class="info df ac my-2">{{svg "octicon-git-commit" 16 "mr-2"}}<a href="{{$.RepoLink}}/commit/{{PathEscape .Commit.ID.String}}">{{ShortSha .Commit.ID.String}}</a> · <span class="commit-message">{{RenderCommitMessage .Commit.CommitMessage $.RepoLink $.Repository.ComposeMetas}}</span> · {{$.i18n.Tr "org.repo_updated"}} {{TimeSince .Commit.Committer.When $.i18n.Lang}}</p>
-							{{end}}
-						{{end}}
-						</td>
-						<td class="right aligned overflow-visible">
-							{{if and $.IsWriter (not $.Repository.IsArchived) (not .IsDeleted)}}
-								<div class="ui basic jump button icon tooltip show-create-branch-modal" data-content="{{$.i18n.Tr "repo.branch.new_branch_from" ($.DefaultBranch)}}" data-branch-from="{{$.DefaultBranch}}" data-branch-from-urlcomponent="{{PathEscapeSegments $.DefaultBranch}}" data-modal="#create-branch-modal" data-position="top right">
-									{{svg "octicon-git-branch"}}
-								</div>
-							{{end}}
-							<div class="ui basic jump dropdown icon button tooltip" data-content="{{$.i18n.Tr "repo.branch.download" ($.DefaultBranch)}}" data-position="top right">
-								{{svg "octicon-download"}}
-								<div class="menu">
-									<a class="item archive-link" href="{{$.RepoLink}}/archive/{{PathEscapeSegments $.DefaultBranch}}.zip" rel="nofollow">{{svg "octicon-file-zip"}}&nbsp;ZIP</a>
-									<a class="item archive-link" href="{{$.RepoLink}}/archive/{{PathEscapeSegments $.DefaultBranch}}.tar.gz" rel="nofollow">{{svg "octicon-file-zip"}}&nbsp;TAR.GZ</a>
+								<a href="{{.RepoLink}}/src/branch/{{PathEscapeSegments .DefaultBranch}}">{{.DefaultBranch}}</a>
+								<p class="info df ac my-2">{{svg "octicon-git-commit" 16 "mr-2"}}<a href="{{.RepoLink}}/commit/{{PathEscape .DefaultBranchBranch.Commit.ID.String}}">{{ShortSha .DefaultBranchBranch.Commit.ID.String}}</a> · <span class="commit-message">{{RenderCommitMessage .DefaultBranchBranch.Commit.CommitMessage .RepoLink .Repository.ComposeMetas}}</span> · {{.i18n.Tr "org.repo_updated"}} {{TimeSince .DefaultBranchBranch.Commit.Committer.When .i18n.Lang}}</p>
+							</td>
+							<td class="right aligned overflow-visible">
+								{{if and $.IsWriter (not $.Repository.IsArchived) (not .IsDeleted)}}
+									<div class="ui basic jump button icon tooltip show-create-branch-modal" data-content="{{$.i18n.Tr "repo.branch.new_branch_from" ($.DefaultBranch)}}" data-branch-from="{{$.DefaultBranch}}" data-branch-from-urlcomponent="{{PathEscapeSegments $.DefaultBranch}}" data-modal="#create-branch-modal" data-position="top right">
+										{{svg "octicon-git-branch"}}
+									</div>
+								{{end}}
+								<div class="ui basic jump dropdown icon button tooltip" data-content="{{$.i18n.Tr "repo.branch.download" ($.DefaultBranch)}}" data-position="top right">
+									{{svg "octicon-download"}}
+									<div class="menu">
+										<a class="item archive-link" href="{{$.RepoLink}}/archive/{{PathEscapeSegments $.DefaultBranch}}.zip" rel="nofollow">{{svg "octicon-file-zip"}}&nbsp;ZIP</a>
+										<a class="item archive-link" href="{{$.RepoLink}}/archive/{{PathEscapeSegments $.DefaultBranch}}.tar.gz" rel="nofollow">{{svg "octicon-file-zip"}}&nbsp;TAR.GZ</a>
+									</div>
 								</div>
-							</div>
-						</td>
-					</tr>
-				</tbody>
-			</table>
-		</div>
+							</td>
+						</tr>
+					</tbody>
+				</table>
+			</div>
+		{{end}}
 
 		{{if gt (len .Branches) 1}}
 			<h4 class="ui top attached header">
@@ -65,7 +63,7 @@
 									{{end}}
 									</td>
 									<td class="three wide ui">
-										{{if not .IsDeleted}}
+										{{if and (not .IsDeleted) $.DefaultBranchBranch}}
 										<div class="commit-divergence">
 											<div class="bar-group">
 												<div class="count count-behind">{{.CommitsBehind}}</div>