func patch(c *object.Commit, path string) ([]diffmatchpatch.Diff, error) {
// get contents of the file in the commit
file, err := c.File(path)
if err != nil {
return nil, err
}
content, err := file.Contents()
if err != nil {
return nil, err
}
// get contents of the file in the first parent of the commit
var contentParent string
iter := c.Parents()
parent, err := iter.Next()
if err != nil {
return nil, err
}
file, err = parent.File(path)
if err != nil {
contentParent = ""
} else {
contentParent, err = file.Contents()
if err != nil {
return nil, err
}
}
// compare the contents of parent and child
return diff.Do(content, contentParent), nil
}
// TODO: benchmark this making git.object.Commit.parent public instead of using
// an iterator
func parentsContainingPath(path string, c *object.Commit) []*object.Commit {
var result []*object.Commit
iter := c.Parents()
for {
parent, err := iter.Next()
if err != nil {
if err == io.EOF {
return result
}
panic("unreachable")
}
if _, err := parent.File(path); err == nil {
result = append(result, parent)
}
}
}