source: expose Ancestor in GitInfo

Also updates docs and bumps bep/gitmap to v1.7.0

Closes #5693

Author: jenbroek

Diff for: docs/content/en/methods/page/GitInfo.md

@@ -123,6 +123,22 @@ This is configurable. See [details].
 {{ end }}
 ```
 
+###### Ancestor
+
+(`*source.GitInfo`) The file-filtered ancestor commit, if any.
+
+```go-html-template
+{{ partial "inline/changelog.html" .GitInfo }} → 2023-10-09: Add tutorials
+                                                 2025-03-26: Edit GitInfo docs
+
+{{ define "_partials/inline/changelog.html" }}
+  {{ with . }}
+    {{ partial "inline/changelog.html" .Ancestor }}
+    {{ .CommitDate.Format "2006-01-02" }}: {{ .Subject }}<br>
+  {{ end }}
+{{ end }}
+```
+
 ## Last modified date
 
 By default, when `enableGitInfo` is `true`, the `Lastmod` method on a `Page` object returns the Git AuthorDate of the last commit that included the file.

Diff for: go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/aws/aws-sdk-go-v2/service/cloudfront v1.44.10
 	github.com/bep/clocks v0.5.0
 	github.com/bep/debounce v1.2.0
-	github.com/bep/gitmap v1.6.0
+	github.com/bep/gitmap v1.7.0
 	github.com/bep/goat v0.5.0
 	github.com/bep/godartsass/v2 v2.5.0
 	github.com/bep/golibsass v1.2.0

Diff for: go.sum

@@ -125,8 +125,8 @@ github.com/bep/clocks v0.5.0 h1:hhvKVGLPQWRVsBP/UB7ErrHYIO42gINVbvqxvYTPVps=
 github.com/bep/clocks v0.5.0/go.mod h1:SUq3q+OOq41y2lRQqH5fsOoxN8GbxSiT6jvoVVLCVhU=
 github.com/bep/debounce v1.2.0 h1:wXds8Kq8qRfwAOpAxHrJDbCXgC5aHSzgQb/0gKsHQqo=
 github.com/bep/debounce v1.2.0/go.mod h1:H8yggRPQKLUhUoqrJC1bO2xNya7vanpDl7xR3ISbCJ0=
-github.com/bep/gitmap v1.6.0 h1:sDuQMm9HoTL0LtlrfxjbjgAg2wHQd4nkMup2FInYzhA=
-github.com/bep/gitmap v1.6.0/go.mod h1:n+3W1f/rot2hynsqEGxGMErPRgT41n9CkGuzPvz9cIw=
+github.com/bep/gitmap v1.7.0 h1:jvPnRQv5RG6IDPrwoDiwAhTE/DmdEkOW4poFeUYmjI8=
+github.com/bep/gitmap v1.7.0/go.mod h1:n+3W1f/rot2hynsqEGxGMErPRgT41n9CkGuzPvz9cIw=
 github.com/bep/goat v0.5.0 h1:S8jLXHCVy/EHIoCY+btKkmcxcXFd34a0Q63/0D4TKeA=
 github.com/bep/goat v0.5.0/go.mod h1:Md9x7gRxiWKs85yHlVTvHQw9rg86Bm+Y4SuYE8CTH7c=
 github.com/bep/godartsass/v2 v2.5.0 h1:tKRvwVdyjCIr48qgtLa4gHEdtRkPF8H1OeEhJAEv7xg=

Diff for: source/fileInfo.go

@@ -155,7 +155,23 @@ func NewFileInfo(fi hugofs.FileMetaInfo) *File {
 }
 
 func NewGitInfo(info gitmap.GitInfo) GitInfo {
-	return GitInfo(info)
+	gi := GitInfo{
+		Hash:            info.Hash,
+		AbbreviatedHash: info.AbbreviatedHash,
+		Subject:         info.Subject,
+		AuthorName:      info.AuthorName,
+		AuthorEmail:     info.AuthorEmail,
+		AuthorDate:      info.AuthorDate,
+		CommitDate:      info.CommitDate,
+		Body:            info.Body,
+	}
+
+	if info.Ancestor != nil {
+		anc := NewGitInfo(*info.Ancestor)
+		gi.Ancestor = &anc
+	}
+
+	return gi
 }
 
 // GitInfo provides information about a version controlled source file.
@@ -176,10 +192,12 @@ type GitInfo struct {
 	CommitDate time.Time `json:"commitDate"`
 	// The commit message's body.
 	Body string `json:"body"`
+	// The file-filtered ancestor commit, if any.
+	Ancestor *GitInfo `json:"ancestor"`
 }
 
 // IsZero returns true if the GitInfo is empty,
 // meaning it will also be falsy in the Go templates.
-func (g GitInfo) IsZero() bool {
-	return g.Hash == ""
+func (g *GitInfo) IsZero() bool {
+	return g == nil || g.Hash == ""
 }