This patch adapts https://github.com/caglar10ur/Hound/commit/a9208072a0444cd562592ca1bf348bf816ba4c2a to work on https://github.com/etsy/hound to allow indexing and searching on multiple branches...

0001-Add-the-ability-to-specify-multiple-branches-and-sea.patch

From 51270ab670ce3b4c7d4987e4f28f9615094bae31 Mon Sep 17 00:00:00 2001
From: Abhinav Tripathi <genuinelucifer@gmail.com>
Date: Wed, 3 Apr 2019 15:13:05 +0900
Subject: [PATCH] Add the ability to specify multiple branches and search
 through those

Adapted the patch at https://github.com/caglar10ur/Hound/commit/a9208072a0444cd562592ca1bf348bf816ba4c2a
and added the option to specify allbranches search
---
 api/api.go             | 35 ++++++++++++++++++-----------
 client/client.go       |  5 +++--
 config/config.go       |  3 ++-
 index/index.go         |  1 +
 searcher/searcher.go   | 51 +++++++++++++++++++++++++-----------------
 ui/assets/js/common.js |  3 ++-
 ui/assets/js/hound.js  | 49 ++++++++++++++++++++++++++++++++++------
 vcs/bzr.go             |  4 ++--
 vcs/git.go             | 33 +++++++++++++++++++++++----
 vcs/hg.go              |  4 ++--
 vcs/svn.go             |  4 ++--
 vcs/vcs.go             | 10 ++++-----
 12 files changed, 143 insertions(+), 59 deletions(-)

diff --git a/api/api.go b/api/api.go
index 017eec2..a7f424e 100644
--- a/api/api.go
+++ b/api/api.go
@@ -100,21 +100,27 @@ func parseAsBool(v string) bool {
 	return v == "true" || v == "1" || v == "fosho"
 }
 
-func parseAsRepoList(v string, idx map[string]*searcher.Searcher) []string {
+// If all branches are not selected then only search in master branches
+func doSearchInRepo(reposToSearch string, repo string, allb bool) bool {
+	if reposToSearch != "*" && !strings.Contains(reposToSearch, repo) {
+		return false
+	}
+	if allb == true {
+		return true
+	}
+	if strings.HasSuffix(repo, "@master") {
+		return true
+	}
+	return false
+}
+
+func parseAsRepoList(v string, allb bool, idx map[string]*searcher.Searcher) []string {
 	v = strings.TrimSpace(v)
 	var repos []string
-	if v == "*" {
-		for repo := range idx {
+	for repo := range idx {
+		if doSearchInRepo(v, repo, allb) {
 			repos = append(repos, repo)
 		}
-		return repos
-	}
-
-	for _, repo := range strings.Split(v, ",") {
-		if idx[repo] == nil {
-			continue
-		}
-		repos = append(repos, repo)
 	}
 	return repos
 }
@@ -174,11 +180,13 @@ func Setup(m *http.ServeMux, idx map[string]*searcher.Searcher) {
 		var opt index.SearchOptions
 
 		stats := parseAsBool(r.FormValue("stats"))
-		repos := parseAsRepoList(r.FormValue("repos"), idx)
 		query := r.FormValue("q")
 		opt.Offset, opt.Limit = parseRangeValue(r.FormValue("rng"))
 		opt.FileRegexp = r.FormValue("files")
 		opt.IgnoreCase = parseAsBool(r.FormValue("i"))
+		opt.AllBranches = parseAsBool(r.FormValue("allb"))
+		repos := parseAsRepoList(r.FormValue("repos"), opt.AllBranches, idx)
+
 		opt.LinesOfContext = parseAsUintValue(
 			r.FormValue("ctx"),
 			0,
@@ -227,7 +235,8 @@ func Setup(m *http.ServeMux, idx map[string]*searcher.Searcher) {
 			return
 		}
 
-		repos := parseAsRepoList(r.FormValue("repos"), idx)
+		var allBranches = parseAsBool(r.FormValue("allb"))
+		repos := parseAsRepoList(r.FormValue("repos"), allBranches, idx)
 
 		for _, repo := range repos {
 			searcher := idx[repo]
diff --git a/client/client.go b/client/client.go
index 85bbff8..49c32da 100644
--- a/client/client.go
+++ b/client/client.go
@@ -3,12 +3,13 @@ package client
 import (
 	"encoding/json"
 	"fmt"
-	"github.com/etsy/hound/config"
-	"github.com/etsy/hound/index"
 	"net/http"
 	"net/url"
 	"regexp"
 	"strings"
+
+	"github.com/etsy/hound/config"
+	"github.com/etsy/hound/index"
 )
 
 type Response struct {
diff --git a/config/config.go b/config/config.go
index 1dce70a..7993be2 100644
--- a/config/config.go
+++ b/config/config.go
@@ -13,7 +13,7 @@ const (
 	defaultPushEnabled           = false
 	defaultPollEnabled           = true
 	defaultVcs                   = "git"
-	defaultBaseUrl               = "{url}/blob/master/{path}{anchor}"
+	defaultBaseUrl               = "{url}/blob/{branch}/{path}{anchor}"
 	defaultAnchor                = "#L{line}"
 	defaultHealthChekURI         = "/healthz"
 )
@@ -25,6 +25,7 @@ type UrlPattern struct {
 
 type Repo struct {
 	Url               string         `json:"url"`
+	Branches          []string       `json:"branches"`
 	MsBetweenPolls    int            `json:"ms-between-poll"`
 	Vcs               string         `json:"vcs"`
 	VcsConfigMessage  *SecretMessage `json:"vcs-config"`
diff --git a/index/index.go b/index/index.go
index 8b77369..c39e184 100644
--- a/index/index.go
+++ b/index/index.go
@@ -46,6 +46,7 @@ type SearchOptions struct {
 	FileRegexp     string
 	Offset         int
 	Limit          int
+	AllBranches    bool
 }
 
 type Match struct {
diff --git a/searcher/searcher.go b/searcher/searcher.go
index 4cb706a..05c47d3 100644
--- a/searcher/searcher.go
+++ b/searcher/searcher.go
@@ -52,7 +52,7 @@ type limiter chan bool
  */
 type foundRefs struct {
 	refs    []*index.IndexRef
-	claimed map[*index.IndexRef]bool
+	claimed *sync.Map
 }
 
 func makeLimiter(n int) limiter {
@@ -85,7 +85,7 @@ func (r *foundRefs) find(url, rev string) *index.IndexRef {
  * collected at the end of startup.
  */
 func (r *foundRefs) claim(ref *index.IndexRef) {
-	r.claimed[ref] = true
+	r.claimed.Store(ref, true)
 }
 
 /**
@@ -94,7 +94,7 @@ func (r *foundRefs) claim(ref *index.IndexRef) {
  */
 func (r *foundRefs) removeUnclaimed() error {
 	for _, ref := range r.refs {
-		if r.claimed[ref] {
+		if _, ok := r.claimed.Load(ref); ok {
 			continue
 		}
 
@@ -216,7 +216,7 @@ func findExistingRefs(dbpath string) (*foundRefs, error) {
 
 	return &foundRefs{
 		refs:    refs,
-		claimed: map[*index.IndexRef]bool{},
+		claimed: new(sync.Map),
 	}, nil
 }
 
@@ -262,8 +262,8 @@ func hashFor(name string) string {
 }
 
 // Create a normalized name for the vcs directory of this repo.
-func vcsDirFor(repo *config.Repo) string {
-	return fmt.Sprintf("vcs-%s", hashFor(repo.Url))
+func vcsDirFor(repo *config.Repo, branch string) string {
+	return fmt.Sprintf("vcs-%s-%s", hashFor(repo.Url), branch)
 }
 
 func init() {
@@ -286,14 +286,20 @@ func MakeAll(cfg *config.Config) (map[string]*Searcher, map[string]error, error)
 
 	lim := makeLimiter(cfg.MaxConcurrentIndexers)
 
-	n := len(cfg.Repos)
+	n := 0
+	for _, repo := range cfg.Repos {
+		n = n + len(repo.Branches)
+	}
+
 	// Channel to receive the results from newSearcherConcurrent function.
 	resultCh := make(chan searcherResult, n)
 
 	// Start new searchers for all repos in different go routines while
 	// respecting cfg.MaxConcurrentIndexers.
 	for name, repo := range cfg.Repos {
-		go newSearcherConcurrent(cfg.DbPath, name, repo, refs, lim, resultCh)
+		for _, branch := range repo.Branches {
+			go newSearcherConcurrent(cfg.DbPath, name, repo, branch, refs, lim, resultCh)
+		}
 	}
 
 	// Collect the results on resultCh channel for all repos.
@@ -321,8 +327,8 @@ func MakeAll(cfg *config.Config) (map[string]*Searcher, map[string]error, error)
 
 // Creates a new Searcher that is available for searches as soon as this returns.
 // This will pull or clone the target repo and start watching the repo for changes.
-func New(dbpath, name string, repo *config.Repo) (*Searcher, error) {
-	s, err := newSearcher(dbpath, name, repo, &foundRefs{}, makeLimiter(1))
+func New(dbpath, name string, repo *config.Repo, branch string) (*Searcher, error) {
+	s, err := newSearcher(dbpath, name, repo, branch, &foundRefs{}, makeLimiter(1))
 	if err != nil {
 		return nil, err
 	}
@@ -337,6 +343,7 @@ func updateAndReindex(
 	s *Searcher,
 	dbpath,
 	vcsDir,
+	branch,
 	name,
 	rev string,
 	wd *vcs.WorkDir,
@@ -348,10 +355,10 @@ func updateAndReindex(
 	defer lim.Release()
 
 	repo := s.Repo
-	newRev, err := wd.PullOrClone(vcsDir, repo.Url)
+	newRev, err := wd.PullOrClone(vcsDir, repo.Url, branch)
 
 	if err != nil {
-		log.Printf("vcs pull error (%s - %s): %s", name, repo.Url, err)
+		log.Printf("vcs pull error (%s - %s - %s): %s", name, branch, repo.Url, err)
 		return rev, false
 	}
 
@@ -388,12 +395,13 @@ func updateAndReindex(
 func newSearcher(
 	dbpath, name string,
 	repo *config.Repo,
+	branch string,
 	refs *foundRefs,
 	lim limiter) (*Searcher, error) {
 
-	vcsDir := filepath.Join(dbpath, vcsDirFor(repo))
+	vcsDir := filepath.Join(dbpath, vcsDirFor(repo, branch))
 
-	log.Printf("Searcher started for %s", name)
+	log.Printf("Searcher started for %s@%s", name, branch)
 
 	wd, err := vcs.New(repo.Vcs, repo.VcsConfig())
 	if err != nil {
@@ -405,7 +413,7 @@ func newSearcher(
 		SpecialFiles:    wd.SpecialFiles(),
 	}
 
-	rev, err := wd.PullOrClone(vcsDir, repo.Url)
+	rev, err := wd.PullOrClone(vcsDir, repo.Url, branch)
 	if err != nil {
 		return nil, err
 	}
@@ -414,7 +422,9 @@ func newSearcher(
 	ref := refs.find(repo.Url, rev)
 	if ref == nil {
 		idxDir = nextIndexDir(dbpath)
+		fmt.Printf("Could not find ref for url: %s and branch: %s\n", repo.Url, branch)
 	} else {
+		fmt.Printf("For url: %s and branch: %s found ref with dir: %s\n", repo.Url, branch, ref.Dir())
 		idxDir = ref.Dir()
 		refs.claim(ref)
 	}
@@ -464,7 +474,7 @@ func newSearcher(
 			}
 
 			// attempt to update and reindex this searcher
-			newRev, ok := updateAndReindex(s, dbpath, vcsDir, name, rev, wd, opt, lim)
+			newRev, ok := updateAndReindex(s, dbpath, vcsDir, branch, name, rev, wd, opt, lim)
 			if !ok {
 				continue
 			}
@@ -490,6 +500,7 @@ func newSearcher(
 func newSearcherConcurrent(
 	dbpath, name string,
 	repo *config.Repo,
+	branch string,
 	refs *foundRefs,
 	lim limiter,
 	resultCh chan searcherResult) {
@@ -498,17 +509,17 @@ func newSearcherConcurrent(
 	lim.Acquire()
 	defer lim.Release()
 
-	s, err := newSearcher(dbpath, name, repo, refs, lim)
+	s, err := newSearcher(dbpath, name, repo, branch, refs, lim)
 	if err != nil {
 		resultCh <- searcherResult{
-			name:     name,
-			err:      err,
+			name: name + "@" + branch,
+			err:  err,
 		}
 		return
 	}
 
 	resultCh <- searcherResult{
-		name:     name,
+		name:     name + "@" + branch,
 		searcher: s,
 	}
 }
diff --git a/ui/assets/js/common.js b/ui/assets/js/common.js
index 683ff7b..7a6e2f1 100644
--- a/ui/assets/js/common.js
+++ b/ui/assets/js/common.js
@@ -5,7 +5,7 @@ export function ExpandVars(template, values) {
     return template;
 };
 
-export function UrlToRepo(repo, path, line, rev) {
+export function UrlToRepo(repo, branch, path, line, rev) {
     var url = repo.url.replace(/\.git$/, ''),
         pattern = repo['url-pattern'],
         filename = path.substring(path.lastIndexOf('/') + 1),
@@ -34,6 +34,7 @@ export function UrlToRepo(repo, path, line, rev) {
     // I'm sure there is a nicer React/jsx way to do this:
     return ExpandVars(pattern['base-url'], {
         url : url,
+        branch: branch,
         path: path,
         rev: rev,
         anchor: anchor
diff --git a/ui/assets/js/hound.js b/ui/assets/js/hound.js
index a953aa2..57aa24a 100644
--- a/ui/assets/js/hound.js
+++ b/ui/assets/js/hound.js
@@ -70,7 +70,8 @@ var ParamsFromQueryString = function(qs, params) {
 var ParamsFromUrl = function(params) {
   params = params || {
     q: '',
-    i: 'nope',
+    i: 'fosho',
+    allb: 'nope',
     files: '',
     repos: '*'
   };
@@ -165,6 +166,26 @@ var Model = {
     if (params.repos === '') {
       params.repos = '*';
     }
+    else {
+      // Replace repo names with repo@branch strings
+      let allRepos = params.repos.split(',');
+      let reposWithBranches = [];
+      for (let i = 0; i < allRepos.length; ++i) {
+        let repo = allRepos[i];
+        let allBranches = this.repos[repo]["branches"];
+        if (params.allb)
+          allBranches.forEach ( function (b) {
+            reposWithBranches.push(repo + "@" + b);
+          })
+        else if (allBranches.includes("develop"))
+          reposWithBranches.push(repo + "@develop");
+      }
+      params.repos = reposWithBranches.join(",");
+    }
+
+    if(params.files == '') {
+      params.files = "(\.bat|\.conf|\.css|\.csv|\.cql|\.erb|\.go|\.groovy|\.haml|\.hogan|\.hs|\.htm|\.html|\.j2|\.java|\.js|\.json|\.jsp|\.less|\.md|\.mustache|\.pas|\.php|\.properties|\.py|\.rb|\.scala|\.scss|\.sh|\.sql|\.txt|\.xml|\.yaml|\.yml|Dockerfile)";
+    }
 
     _this.params = params;
 
@@ -172,7 +193,7 @@ var Model = {
     // sending it to the server and having the server do work
     // to produce an error, we simply return empty results
     // immediately in the client.
-    if (params.q == '') {
+    if (params.q == '' || params.repos == '') {
       _this.results = [];
       _this.resultsByRepo = {};
       _this.didSearch.raise(_this, _this.Results);
@@ -189,7 +210,6 @@ var Model = {
           _this.didError.raise(_this, data.Error);
           return;
         }
-
         var matches = data.Results,
             stats = data.Stats,
             results = [];
@@ -223,7 +243,6 @@ var Model = {
           Total: Date.now() - startedAt,
           Files: stats.FilesOpened
         };
-
         _this.didSearch.raise(_this, _this.results, _this.stats);
       },
       error: function(xhr, status, err) {
@@ -269,6 +288,7 @@ var Model = {
   },
 
   NameForRepo: function(repo) {
+    repo = repo.split("@")[0];
     var info = this.repos[repo];
     if (!info) {
       return repo;
@@ -290,8 +310,11 @@ var Model = {
     return url.substring(bx + 1, ax) + ' / ' + name;
   },
 
-  UrlToRepo: function(repo, path, line, rev) {
-    return UrlToRepo(this.repos[repo], path, line, rev);
+  UrlToRepo: function(repo_branch, path, line, rev) {
+    let repo_n_branch = repo_branch.split("@");
+    let repo = repo_n_branch[0];
+    let branch = repo_n_branch[1];
+    return UrlToRepo(this.repos[repo], branch, path, line, rev);
   }
 
 };
@@ -389,16 +412,19 @@ var SearchBar = React.createClass({
       q : this.refs.q.getDOMNode().value.trim(),
       files : this.refs.files.getDOMNode().value.trim(),
       repos : repos.join(','),
-      i: this.refs.icase.getDOMNode().checked ? 'fosho' : 'nope'
+      i: this.refs.icase.getDOMNode().checked ? 'fosho' : 'nope',
+      allb: this.refs.allb.getDOMNode().checked ? 'fosho' : 'nope'
     };
   },
   setParams: function(params) {
     var q = this.refs.q.getDOMNode(),
         i = this.refs.icase.getDOMNode(),
+        allb = this.refs.allb.getDOMNode(),
         files = this.refs.files.getDOMNode();
 
     q.value = params.q;
     i.checked = ParamValueToBool(params.i);
+    allb.checked = ParamValueToBool(params.allb);
     files.value = params.files;
   },
   hasAdvancedValues: function() {
@@ -501,6 +527,12 @@ var SearchBar = React.createClass({
                 <input id="ignore-case" type="checkbox" ref="icase" />
               </div>
             </div>
+            <div className="field">
+              <label htmlFor="all-branches">All branches</label>
+              <div className="field-input">
+                <input id="all-branches" type="checkbox" ref="allb" />
+              </div>
+            </div>
             <div className="field">
               <label className="multiselect_label" htmlFor="repos">Select Repo</label>
               <div className="field-input">
@@ -758,6 +790,7 @@ var App = React.createClass({
     this.setState({
       q: params.q,
       i: params.i,
+      allb: params.allb,
       files: params.files,
       repos: repos
     });
@@ -812,6 +845,7 @@ var App = React.createClass({
     var path = location.pathname +
       '?q=' + encodeURIComponent(params.q) +
       '&i=' + encodeURIComponent(params.i) +
+      '&allb=' + encodeURIComponent(params.allb) +
       '&files=' + encodeURIComponent(params.files) +
       '&repos=' + params.repos;
     history.pushState({path:path}, '', path);
@@ -822,6 +856,7 @@ var App = React.createClass({
         <SearchBar ref="searchBar"
             q={this.state.q}
             i={this.state.i}
+            allb={this.state.allb}
             files={this.state.files}
             repos={this.state.repos}
             onSearchRequested={this.onSearchRequested} />
diff --git a/vcs/bzr.go b/vcs/bzr.go
index f8acd8d..c12fc9e 100644
--- a/vcs/bzr.go
+++ b/vcs/bzr.go
@@ -43,7 +43,7 @@ func (g *BzrDriver) HeadRev(dir string) (string, error) {
 	return strings.TrimSpace(buf.String()), cmd.Wait()
 }
 
-func (g *BzrDriver) Pull(dir string) (string, error) {
+func (g *BzrDriver) Pull(dir, branch string) (string, error) {
 	cmd := exec.Command("bzr", "pull")
 	cmd.Dir = dir
 	out, err := cmd.CombinedOutput()
@@ -55,7 +55,7 @@ func (g *BzrDriver) Pull(dir string) (string, error) {
 	return g.HeadRev(dir)
 }
 
-func (g *BzrDriver) Clone(dir, url string) (string, error) {
+func (g *BzrDriver) Clone(dir, url, branch string) (string, error) {
 	par, rep := filepath.Split(dir)
 	cmd := exec.Command(
 		"bzr",
diff --git a/vcs/git.go b/vcs/git.go
index f8c6682..c05e7e7 100644
--- a/vcs/git.go
+++ b/vcs/git.go
@@ -61,7 +61,26 @@ func run(desc, dir, cmd string, args ...string) error {
 	return nil
 }
 
-func (g *GitDriver) Pull(dir string) (string, error) {
+func (g *GitDriver) Checkout(dir, branch string) error {
+	cmd := exec.Command("git", "checkout", branch)
+	cmd.Dir = dir
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		log.Printf("Failed to git checkout %s, see output below\n%sContinuing...", dir, out)
+		return err
+	}
+	return nil
+}
+
+func (g *GitDriver) Pull(dir, branch string) (string, error) {
+	if branch == "" {
+		branch = defaultRef
+	}
+
+	if err := g.Checkout(dir, branch); err != nil {
+		return "", err
+	}
+
 	if err := run("git fetch", dir,
 		"git",
 		"fetch",
@@ -69,7 +88,7 @@ func (g *GitDriver) Pull(dir string) (string, error) {
 		"--no-tags",
 		"--depth", "1",
 		"origin",
-		fmt.Sprintf("+%s:remotes/origin/%s", defaultRef, defaultRef)); err != nil {
+		fmt.Sprintf("+%s:remotes/origin/%s", branch, branch)); err != nil {
 		return "", err
 	}
 
@@ -77,18 +96,24 @@ func (g *GitDriver) Pull(dir string) (string, error) {
 		"git",
 		"reset",
 		"--hard",
-		fmt.Sprintf("origin/%s", defaultRef)); err != nil {
+		fmt.Sprintf("origin/%s", branch)); err != nil {
 		return "", err
 	}
 
 	return g.HeadRev(dir)
 }
 
-func (g *GitDriver) Clone(dir, url string) (string, error) {
+func (g *GitDriver) Clone(dir, url, branch string) (string, error) {
+	if branch == "" {
+		branch = defaultRef
+	}
+
 	par, rep := filepath.Split(dir)
 	cmd := exec.Command(
 		"git",
 		"clone",
+		"-b",
+		branch,
 		"--depth", "1",
 		url,
 		rep)
diff --git a/vcs/hg.go b/vcs/hg.go
index 8e13bb1..6f01ec8 100644
--- a/vcs/hg.go
+++ b/vcs/hg.go
@@ -47,7 +47,7 @@ func (g *MercurialDriver) HeadRev(dir string) (string, error) {
 	return strings.TrimSpace(buf.String()), cmd.Wait()
 }
 
-func (g *MercurialDriver) Pull(dir string) (string, error) {
+func (g *MercurialDriver) Pull(dir, branch string) (string, error) {
 	cmd := exec.Command("hg", "pull", "-u")
 	cmd.Dir = dir
 	err := cmd.Run()
@@ -58,7 +58,7 @@ func (g *MercurialDriver) Pull(dir string) (string, error) {
 	return g.HeadRev(dir)
 }
 
-func (g *MercurialDriver) Clone(dir, url string) (string, error) {
+func (g *MercurialDriver) Clone(dir, url, branch string) (string, error) {
 	par, rep := filepath.Split(dir)
 	cmd := exec.Command(
 		"hg",
diff --git a/vcs/svn.go b/vcs/svn.go
index 087aa0f..b8a335f 100644
--- a/vcs/svn.go
+++ b/vcs/svn.go
@@ -54,7 +54,7 @@ func (g *SVNDriver) HeadRev(dir string) (string, error) {
 	return strings.TrimSpace(buf.String()), cmd.Wait()
 }
 
-func (g *SVNDriver) Pull(dir string) (string, error) {
+func (g *SVNDriver) Pull(dir, branch string) (string, error) {
 	cmd := exec.Command(
 		"svn",
 		"update",
@@ -73,7 +73,7 @@ func (g *SVNDriver) Pull(dir string) (string, error) {
 	return g.HeadRev(dir)
 }
 
-func (g *SVNDriver) Clone(dir, url string) (string, error) {
+func (g *SVNDriver) Clone(dir, url, branch string) (string, error) {
 	par, rep := filepath.Split(dir)
 	cmd := exec.Command(
 		"svn",
diff --git a/vcs/vcs.go b/vcs/vcs.go
index 6f2588d..fc2dd6f 100644
--- a/vcs/vcs.go
+++ b/vcs/vcs.go
@@ -16,10 +16,10 @@ var drivers = make(map[string]func(c []byte) (Driver, error))
 type Driver interface {
 
 	// Clone a new working directory.
-	Clone(dir, url string) (string, error)
+	Clone(dir, url, branch string) (string, error)
 
 	// Pull new changes from the server and update the working directory.
-	Pull(dir string) (string, error)
+	Pull(dir, branch string) (string, error)
 
 	// Return the revision at the head of the vcs directory.
 	HeadRev(dir string) (string, error)
@@ -69,9 +69,9 @@ func exists(path string) bool {
 
 // A utility method that carries out the common operation of cloning
 // if the working directory is absent and pulling otherwise.
-func (w *WorkDir) PullOrClone(dir, url string) (string, error) {
+func (w *WorkDir) PullOrClone(dir, url, branch string) (string, error) {
 	if exists(dir) {
-		return w.Pull(dir)
+		return w.Pull(dir, branch)
 	}
-	return w.Clone(dir, url)
+	return w.Clone(dir, url, branch)
 }
-- 
2.17.1

Save the file and use git am < 0001-Add-the-ability-to-specify-multiple-branches-and-sea.patch to apply it. It has been tested on 3rd April 2019 by applying it on top of the latest commit on master branch (commit: hound-search/hound@74ec744).

I don't have any prior experience with golang and just tried to guess and google to make these changes work. Feel free to standardize the code and send an MR to https://github.com/etsy/hound if you wish.