Adds side-by-side diff for images (#6784)

* Adds side-by-side diff for images

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Explain blank imports

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Use complete word for width and height labels on image compare

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Update index.css from master

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Moves ImageInfo to git commit file

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Assign ImageInfo function for template and sets correct target for BeforeSourcePath

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Adds missing comment

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Return error if ImageInfo failed

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Avoid template panic when ImageInfo failed for some reason

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Show file size on image diff

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Removes unused helper function

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Reverts copyright year change

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Close file reader

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Update commit.go

Sets correct data key

* Moves reader.Close() up a few lines

* Updates index.css

* Updates CSS file

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Transfers adjustments for image compare to compare.go file

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Adjusts variable name

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Apply lesshint recommendations

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Do not show old image on image compare if it is not in index of base commit

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Change file size text

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

3 files changed, 98 insertions, 3 deletions

diff --git a/routers/repo/commit.go b/routers/repo/commit.go
index c3181cbe46..919ebabf42 100644
--- a/routers/repo/commit.go
+++ b/routers/repo/commit.go
@@ -240,6 +240,23 @@ func Diff(ctx *context.Context) {
 	ctx.Data["Username"] = userName
 	ctx.Data["Reponame"] = repoName
 	ctx.Data["IsImageFile"] = commit.IsImageFile
+	ctx.Data["ImageInfo"] = func(name string) *git.ImageMetaData {
+		result, err := commit.ImageInfo(name)
+		if err != nil {
+			log.Error("ImageInfo failed: %v", err)
+			return nil
+		}
+		return result
+	}
+	ctx.Data["ImageInfoBase"] = ctx.Data["ImageInfo"]
+	if commit.ParentCount() > 0 {
+		parentCommit, err := ctx.Repo.GitRepo.GetCommit(parents[0])
+		if err != nil {
+			ctx.NotFound("GetParentCommit", err)
+			return
+		}
+		ctx.Data["ImageInfo"] = parentCommit.ImageInfo
+	}
 	ctx.Data["Title"] = commit.Summary() + " · " + base.ShortSha(commitID)
 	ctx.Data["Commit"] = commit
 	ctx.Data["Verification"] = models.ParseCommitWithSignature(commit)
@@ -248,6 +265,7 @@ func Diff(ctx *context.Context) {
 	ctx.Data["Parents"] = parents
 	ctx.Data["DiffNotAvailable"] = diff.NumFiles() == 0
 	ctx.Data["SourcePath"] = setting.AppSubURL + "/" + path.Join(userName, repoName, "src", "commit", commitID)
+	ctx.Data["RawPath"] = setting.AppSubURL + "/" + path.Join(userName, repoName, "raw", "commit", commitID)
 
 	note := &git.Note{}
 	err = git.GetNote(ctx.Repo.GitRepo, commitID, note)
@@ -259,8 +277,8 @@ func Diff(ctx *context.Context) {
 
 	if commit.ParentCount() > 0 {
 		ctx.Data["BeforeSourcePath"] = setting.AppSubURL + "/" + path.Join(userName, repoName, "src", "commit", parents[0])
+		ctx.Data["BeforeRawPath"] = setting.AppSubURL + "/" + path.Join(userName, repoName, "raw", "commit", parents[0])
 	}
-	ctx.Data["RawPath"] = setting.AppSubURL + "/" + path.Join(userName, repoName, "raw", "commit", commitID)
 	ctx.Data["BranchName"], err = commit.GetBranchName()
 	if err != nil {
 		ctx.ServerError("commit.GetBranchName", err)
diff --git a/routers/repo/compare.go b/routers/repo/compare.go
index 4f9a918a7c..7c55dfca30 100644
--- a/routers/repo/compare.go
+++ b/routers/repo/compare.go
@@ -247,6 +247,26 @@ func PrepareCompareDiff(
 		return false
 	}
 
+	baseGitRepo := ctx.Repo.GitRepo
+	baseCommitID := baseBranch
+	if ctx.Data["BaseIsCommit"] == false {
+		if ctx.Data["BaseIsTag"] == true {
+			baseCommitID, err = baseGitRepo.GetTagCommitID(baseBranch)
+		} else {
+			baseCommitID, err = baseGitRepo.GetBranchCommitID(baseBranch)
+		}
+		if err != nil {
+			ctx.ServerError("GetRefCommitID", err)
+			return false
+		}
+	}
+
+	baseCommit, err := baseGitRepo.GetCommit(baseCommitID)
+	if err != nil {
+		ctx.ServerError("GetCommit", err)
+		return false
+	}
+
 	compareInfo.Commits = models.ValidateCommitsWithEmails(compareInfo.Commits)
 	compareInfo.Commits = models.ParseCommitsWithSignature(compareInfo.Commits)
 	compareInfo.Commits = models.ParseCommitsWithStatus(compareInfo.Commits, headRepo)
@@ -272,11 +292,43 @@ func PrepareCompareDiff(
 	ctx.Data["Username"] = headUser.Name
 	ctx.Data["Reponame"] = headRepo.Name
 	ctx.Data["IsImageFile"] = headCommit.IsImageFile
+	ctx.Data["ImageInfo"] = func(name string) *git.ImageMetaData {
+		result, err := headCommit.ImageInfo(name)
+		if err != nil {
+			log.Error("ImageInfo failed: %v", err)
+			return nil
+		}
+		return result
+	}
+	ctx.Data["FileExistsInBaseCommit"] = func(filename string) bool {
+		result, err := baseCommit.HasFile(filename)
+		if err != nil {
+			log.Error(
+				"Error while checking if file \"%s\" exists in base commit \"%s\" (repo: %s): %v",
+				filename,
+				baseCommit,
+				baseGitRepo.Path,
+				err)
+			return false
+		}
+		return result
+	}
+	ctx.Data["ImageInfoBase"] = func(name string) *git.ImageMetaData {
+		result, err := baseCommit.ImageInfo(name)
+		if err != nil {
+			log.Error("ImageInfo failed: %v", err)
+			return nil
+		}
+		return result
+	}
 
 	headTarget := path.Join(headUser.Name, repo.Name)
+	baseTarget := path.Join(ctx.Repo.Owner.Name, ctx.Repo.Repository.Name)
 	ctx.Data["SourcePath"] = setting.AppSubURL + "/" + path.Join(headTarget, "src", "commit", headCommitID)
-	ctx.Data["BeforeSourcePath"] = setting.AppSubURL + "/" + path.Join(headTarget, "src", "commit", compareInfo.MergeBase)
 	ctx.Data["RawPath"] = setting.AppSubURL + "/" + path.Join(headTarget, "raw", "commit", headCommitID)
+	ctx.Data["BeforeSourcePath"] = setting.AppSubURL + "/" + path.Join(baseTarget, "src", "commit", baseCommitID)
+	ctx.Data["BeforeRawPath"] = setting.AppSubURL + "/" + path.Join(baseTarget, "raw", "commit", baseCommitID)
+
 	return false
 }
 
diff --git a/routers/repo/pull.go b/routers/repo/pull.go
index 14d2f50821..14b8670a20 100644
--- a/routers/repo/pull.go
+++ b/routers/repo/pull.go
@@ -535,6 +535,11 @@ func ViewPullFiles(ctx *context.Context) {
 	ctx.Data["Diff"] = diff
 	ctx.Data["DiffNotAvailable"] = diff.NumFiles() == 0
 
+	baseCommit, err := ctx.Repo.GitRepo.GetCommit(startCommitID)
+	if err != nil {
+		ctx.ServerError("GetCommit", err)
+		return
+	}
 	commit, err := gitRepo.GetCommit(endCommitID)
 	if err != nil {
 		ctx.ServerError("GetCommit", err)
@@ -542,9 +547,29 @@ func ViewPullFiles(ctx *context.Context) {
 	}
 
 	ctx.Data["IsImageFile"] = commit.IsImageFile
+	ctx.Data["ImageInfoBase"] = func(name string) *git.ImageMetaData {
+		result, err := baseCommit.ImageInfo(name)
+		if err != nil {
+			log.Error("ImageInfo failed: %v", err)
+			return nil
+		}
+		return result
+	}
+	ctx.Data["ImageInfo"] = func(name string) *git.ImageMetaData {
+		result, err := commit.ImageInfo(name)
+		if err != nil {
+			log.Error("ImageInfo failed: %v", err)
+			return nil
+		}
+		return result
+	}
+
+	baseTarget := path.Join(ctx.Repo.Owner.Name, ctx.Repo.Repository.Name)
 	ctx.Data["SourcePath"] = setting.AppSubURL + "/" + path.Join(headTarget, "src", "commit", endCommitID)
-	ctx.Data["BeforeSourcePath"] = setting.AppSubURL + "/" + path.Join(headTarget, "src", "commit", startCommitID)
 	ctx.Data["RawPath"] = setting.AppSubURL + "/" + path.Join(headTarget, "raw", "commit", endCommitID)
+	ctx.Data["BeforeSourcePath"] = setting.AppSubURL + "/" + path.Join(baseTarget, "src", "commit", startCommitID)
+	ctx.Data["BeforeRawPath"] = setting.AppSubURL + "/" + path.Join(baseTarget, "raw", "commit", startCommitID)
+
 	ctx.Data["RequireHighlightJS"] = true
 	ctx.Data["RequireTribute"] = true
 	if ctx.Data["Assignees"], err = ctx.Repo.Repository.GetAssignees(); err != nil {