From 9a8e34bf9dea66678db8ad4b3d56fbe65be0856f Mon Sep 17 00:00:00 2001
From: Johan Brandhorst <johan.brandhorst@gmail.com>
Date: Mon, 8 Jun 2020 12:33:02 +0100
Subject: [PATCH] Fix import path behaviour when using full path

This change makes protoc-gen-star conform to the behaviour
of protoc-gen-go in the presence of an import_path
parameter that contains slashes.

See https://github.com/golang/protobuf/blob/v1.4.2/protoc-gen-go/generator/generator.go#L637-L643
for evidence of this behaviour in protoc-gen-go.

Fixes #77
---
 lang/go/package.go                                        | 4 ++++
 lang/go/package_test.go                                   | 1 +
 lang/go/testdata/names/full_import_path/import_path.proto | 4 ++++
 lang/go/testdata/names/full_import_path/params            | 1 +
 4 files changed, 10 insertions(+)
 create mode 100644 lang/go/testdata/names/full_import_path/import_path.proto
 create mode 100644 lang/go/testdata/names/full_import_path/params

diff --git a/lang/go/package.go b/lang/go/package.go
index 0597a7e..38ae981 100644
--- a/lang/go/package.go
+++ b/lang/go/package.go
@@ -23,6 +23,10 @@ func (c context) PackageName(node pgs.Node) pgs.Name {
 	// use import_path parameter ONLY if there is no go_package option in the file.
 	if ip := c.p.Str("import_path"); ip != "" &&
 		e.File().Descriptor().GetOptions().GetGoPackage() == "" {
+		// Remove anything before the last slash
+		if i := strings.LastIndex(ip, "/"); i >= 0 {
+			ip = ip[i+1:]
+		}
 		pkg = ip
 	}
 
diff --git a/lang/go/package_test.go b/lang/go/package_test.go
index 72623b0..c7b0252 100644
--- a/lang/go/package_test.go
+++ b/lang/go/package_test.go
@@ -22,6 +22,7 @@ func TestPackageName(t *testing.T) {
 		{"import", "bar"},                    // uses the basename if go_package contains a /
 		{"override", "baz"},                  // if go_package contains ;, use everything to the right
 		{"import_path", "_package"},          // import_path param used if no go_package option
+		{"full_import_path", "buzz"},         // import_path param used if no go_package option. Should use last part of path.
 		{"mapped", "unaffected"},             // M mapped params are ignored for build targets
 		{"import_path_mapped", "go_package"}, // mixed import_path and M parameters should lose to go_package
 		{"transitive_package", "foobar"},     // go_option gets picked up from other files if present
diff --git a/lang/go/testdata/names/full_import_path/import_path.proto b/lang/go/testdata/names/full_import_path/import_path.proto
new file mode 100644
index 0000000..245b082
--- /dev/null
+++ b/lang/go/testdata/names/full_import_path/import_path.proto
@@ -0,0 +1,4 @@
+syntax="proto3";
+package names.import_path;
+
+message ImportPath {}
diff --git a/lang/go/testdata/names/full_import_path/params b/lang/go/testdata/names/full_import_path/params
new file mode 100644
index 0000000..24e2863
--- /dev/null
+++ b/lang/go/testdata/names/full_import_path/params
@@ -0,0 +1 @@
+Mnames/import_path/import_path.proto=foobar,import_path=github.com/fizz/buzz