Multiple packages with the same "leaf" package name can cause go.lint options to be ignored.

[bithoarder]

If multiple packages have the same "leaf" package name (package1/messages/, package2/messages/), then the linting will sometimes be skipped for one of the packages.

It's easiest to describe with a small example:

v1/a/test.proto:

syntax = "proto3";
package test.v1.a;
option go_package = "foo/bar/v1/a";

v2/a/anothertest.proto:

syntax = "proto3";
package test.v1.a;
option go_package = "foo/bar/v2/a";

import "patch/go.proto";
option (go.lint).all = true;

enum SomeEnum {
  SOME_ENUM_UNDEFINED = 0;
  SOME_ENUM_FOO = 1;
}

Then, depending on the order the proto files are supplied to protoc, the generated enum might not be linted.

this failed to lint the enum:
protoc -I . --go-patch_out=plugin=go,paths=source_relative:.make v2\a\anothertest.proto v1\a\test.proto
this works:
protoc -I . --go-patch_out=plugin=go,paths=source_relative:.make v2\a\test.proto v1\a\anothertest.proto

I think this is because Patcher.packagesByName is only keyed by the "leaf" package name, and thus gets overwritten.