From a181ce0035eb2c5b69deb64ac7caa3959a9c5119 Mon Sep 17 00:00:00 2001
From: agammann <161159040+agammann@users.noreply.github.com>
Date: Mon, 19 Oct 2026 21:24:28 -0700
Subject: [PATCH] Handle registry ports in image references

---
 cmd/bashbrew/cmd-children.go      | 13 ++++++++++++-
 cmd/bashbrew/cmd-children_test.go | 26 ++++++++++++++++++++++++++
 pkg/dockerfile/parse.go           |  5 ++++-
 pkg/dockerfile/parse_test.go      | 21 +++++++++++++++++++++
 4 files changed, 63 insertions(+), 2 deletions(-)
 create mode 100644 cmd/bashbrew/cmd-children_test.go

diff --git a/cmd/bashbrew/cmd-children.go b/cmd/bashbrew/cmd-children.go
index 2da21492..1d639456 100644
--- a/cmd/bashbrew/cmd-children.go
+++ b/cmd/bashbrew/cmd-children.go
@@ -102,7 +102,7 @@ func cmdChildren(c *cli.Context) error {
 						arches.add(from, entryArch)
 					}
 					children.add(from, tag)
-					if fromRepo, _, ok := strings.Cut(from, ":"); ok {
+					if fromRepo, ok := repositoryFromImageReference(from); ok {
 						// make sure things like old "alpine" tags that are no longer supported still come up with "bashbrew children alpine"
 						repoTags.add(fromRepo, from)
 					}
@@ -178,3 +178,14 @@ func cmdChildren(c *cli.Context) error {
 
 	return nil
 }
+
+func repositoryFromImageReference(reference string) (string, bool) {
+	repository := reference
+	if digest := strings.IndexByte(repository, '@'); digest >= 0 {
+		repository = repository[:digest]
+	}
+	if tag := strings.LastIndexByte(repository, ':'); tag > strings.LastIndexByte(repository, '/') {
+		repository = repository[:tag]
+	}
+	return repository, repository != reference
+}
diff --git a/cmd/bashbrew/cmd-children_test.go b/cmd/bashbrew/cmd-children_test.go
new file mode 100644
index 00000000..394d46e0
--- /dev/null
+++ b/cmd/bashbrew/cmd-children_test.go
@@ -0,0 +1,26 @@
+package main
+
+import "testing"
+
+func TestRepositoryFromImageReference(t *testing.T) {
+	tests := []struct {
+		reference  string
+		repository string
+		ok         bool
+	}{
+		{"alpine:3.20", "alpine", true},
+		{"registry.example:5000/team/base:latest", "registry.example:5000/team/base", true},
+		{"registry.example:5000/team/base@sha256:123456", "registry.example:5000/team/base", true},
+		{"registry.example:5000/team/base:3@sha256:123456", "registry.example:5000/team/base", true},
+		{"scratch", "scratch", false},
+	}
+
+	for _, test := range tests {
+		t.Run(test.reference, func(t *testing.T) {
+			repository, ok := repositoryFromImageReference(test.reference)
+			if repository != test.repository || ok != test.ok {
+				t.Fatalf("repositoryFromImageReference(%q) = %q, %t; want %q, %t", test.reference, repository, ok, test.repository, test.ok)
+			}
+		})
+	}
+}
diff --git a/pkg/dockerfile/parse.go b/pkg/dockerfile/parse.go
index cba566c8..6eed460b 100644
--- a/pkg/dockerfile/parse.go
+++ b/pkg/dockerfile/parse.go
@@ -174,7 +174,10 @@ func ParseReader(dockerfile io.Reader) (Metadata, error) {
 }
 
 func latestizeRepoTag(repoTag string) string {
-	if repoTag != "scratch" && strings.IndexRune(repoTag, ':') < 0 {
+	if repoTag == "scratch" || strings.Contains(repoTag, "@") {
+		return repoTag
+	}
+	if strings.LastIndexByte(repoTag, ':') <= strings.LastIndexByte(repoTag, '/') {
 		return repoTag + ":latest"
 	}
 	return repoTag
diff --git a/pkg/dockerfile/parse_test.go b/pkg/dockerfile/parse_test.go
index ddda9711..14a9b815 100644
--- a/pkg/dockerfile/parse_test.go
+++ b/pkg/dockerfile/parse_test.go
@@ -31,6 +31,27 @@ func TestParse(t *testing.T) {
 				Froms: []string{"bash:5"},
 			},
 		},
+		{
+			name:       "untagged image from registry with port",
+			dockerfile: `FROM registry.example:5000/team/base`,
+			metadata: dockerfile.Metadata{
+				Froms: []string{"registry.example:5000/team/base:latest"},
+			},
+		},
+		{
+			name:       "tagged image from registry with port",
+			dockerfile: `FROM registry.example:5000/team/base:3`,
+			metadata: dockerfile.Metadata{
+				Froms: []string{"registry.example:5000/team/base:3"},
+			},
+		},
+		{
+			name:       "digest image from registry with port",
+			dockerfile: `FROM registry.example:5000/team/base@sha256:123456`,
+			metadata: dockerfile.Metadata{
+				Froms: []string{"registry.example:5000/team/base@sha256:123456"},
+			},
+		},
 		{
 			name: "comments+whitespace+continuation",
 			dockerfile: `