Restore detection of branches are equal on compare page (#14586)

Somehow the test for detecting if branches are equal broke
this PR restores this functionality.

Fix #14502

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

1 files changed, 16 insertions, 3 deletions

diff --git a/modules/git/repo_compare.go b/modules/git/repo_compare.go
index 5f92bc7714..3255e68392 100644
--- a/modules/git/repo_compare.go
+++ b/modules/git/repo_compare.go
@@ -20,9 +20,11 @@ import (
 
 // CompareInfo represents needed information for comparing references.
 type CompareInfo struct {
-	MergeBase string
-	Commits   *list.List
-	NumFiles  int
+	MergeBase    string
+	BaseCommitID string
+	HeadCommitID string
+	Commits      *list.List
+	NumFiles     int
 }
 
 // GetMergeBase checks and returns merge base of two branches and the reference used as base.
@@ -66,8 +68,18 @@ func (repo *Repository) GetCompareInfo(basePath, baseBranch, headBranch string)
 	}
 
 	compareInfo := new(CompareInfo)
+
+	compareInfo.HeadCommitID, err = GetFullCommitID(repo.Path, headBranch)
+	if err != nil {
+		compareInfo.HeadCommitID = headBranch
+	}
+
 	compareInfo.MergeBase, remoteBranch, err = repo.GetMergeBase(tmpRemote, baseBranch, headBranch)
 	if err == nil {
+		compareInfo.BaseCommitID, err = GetFullCommitID(repo.Path, remoteBranch)
+		if err != nil {
+			compareInfo.BaseCommitID = remoteBranch
+		}
 		// We have a common base - therefore we know that ... should work
 		logs, err := NewCommand("log", compareInfo.MergeBase+"..."+headBranch, prettyLogFormat).RunInDirBytes(repo.Path)
 		if err != nil {
@@ -83,6 +95,7 @@ func (repo *Repository) GetCompareInfo(basePath, baseBranch, headBranch string)
 		if err != nil {
 			compareInfo.MergeBase = remoteBranch
 		}
+		compareInfo.BaseCommitID = compareInfo.MergeBase
 	}
 
 	// Count number of changed files.