cmd/go: match go-import package prefixes by slash

The existing implementation for path collision resolution would
incorrectly determine that:

    example.org/aa

collides with:

    example.org/a

This change splits by slash rather than comparing on a byte-by-byte
basis.

Fixes: #15947
Change-Id: I18b3aaafbc787c81253203cf1328bb3c4420a0c4
Reviewed-on: https://go-review.googlesource.com/23732
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>

diff --git a/src/cmd/go/vcs.go b/src/cmd/go/vcs.go
index 10b8cf8c49dcfa39b446c52b01d403d86f611489..f7c34de5762be244e28be21c5013465e64664dac 100644 (file)
--- a/src/cmd/go/vcs.go
+++ b/src/cmd/go/vcs.go
@@ -779,15 +779,31 @@ type metaImport struct {
 // errNoMatch is returned from matchGoImport when there's no applicable match.
 var errNoMatch = errors.New("no import match")
 
+func splitPathHasPrefix(path, prefix []string) bool {
+       if len(path) < len(prefix) {
+               return false
+       }
+       for i, p := range prefix {
+               if path[i] != p {
+                       return false
+               }
+       }
+       return true
+}
+
 // matchGoImport returns the metaImport from imports matching importPath.
 // An error is returned if there are multiple matches.
 // errNoMatch is returned if none match.
 func matchGoImport(imports []metaImport, importPath string) (_ metaImport, err error) {
        match := -1
+       imp := strings.Split(importPath, "/")
        for i, im := range imports {
-               if !strings.HasPrefix(importPath, im.Prefix) {
+               pre := strings.Split(im.Prefix, "/")
+
+               if !splitPathHasPrefix(imp, pre) {
                        continue
                }
+
                if match != -1 {
                        err = fmt.Errorf("multiple meta tags match import path %q", importPath)
                        return

diff --git a/src/cmd/go/vcs_test.go b/src/cmd/go/vcs_test.go
index 06650608ba40a84f0e15743c12a93c8d39b6d1f1..25e3866df06d771e59139d40e09e97dde8ae0a90 100644 (file)
--- a/src/cmd/go/vcs_test.go
+++ b/src/cmd/go/vcs_test.go
@@ -5,6 +5,7 @@
 package main
 
 import (
+       "errors"
        "internal/testenv"
        "io/ioutil"
        "os"
@@ -227,3 +228,96 @@ func TestIsSecure(t *testing.T) {
                }
        }
 }
+
+func TestMatchGoImport(t *testing.T) {
+       tests := []struct {
+               imports []metaImport
+               path    string
+               mi      metaImport
+               err     error
+       }{
+               {
+                       imports: []metaImport{
+                               {Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                       },
+                       path: "example.com/user/foo",
+                       mi:   metaImport{Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+               },
+               {
+                       imports: []metaImport{
+                               {Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                       },
+                       path: "example.com/user/foo/",
+                       mi:   metaImport{Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+               },
+               {
+                       imports: []metaImport{
+                               {Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                               {Prefix: "example.com/user/fooa", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                       },
+                       path: "example.com/user/foo",
+                       mi:   metaImport{Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+               },
+               {
+                       imports: []metaImport{
+                               {Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                               {Prefix: "example.com/user/fooa", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                       },
+                       path: "example.com/user/fooa",
+                       mi:   metaImport{Prefix: "example.com/user/fooa", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+               },
+               {
+                       imports: []metaImport{
+                               {Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                               {Prefix: "example.com/user/foo/bar", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                       },
+                       path: "example.com/user/foo/bar",
+                       err:  errors.New("should not be allowed to create nested repo"),
+               },
+               {
+                       imports: []metaImport{
+                               {Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                               {Prefix: "example.com/user/foo/bar", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                       },
+                       path: "example.com/user/foo/bar/baz",
+                       err:  errors.New("should not be allowed to create nested repo"),
+               },
+               {
+                       imports: []metaImport{
+                               {Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                               {Prefix: "example.com/user/foo/bar", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                       },
+                       path: "example.com/user/foo/bar/baz/qux",
+                       err:  errors.New("should not be allowed to create nested repo"),
+               },
+               {
+                       imports: []metaImport{
+                               {Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                               {Prefix: "example.com/user/foo/bar", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                       },
+                       path: "example.com/user/foo/bar/baz/",
+                       err:  errors.New("should not be allowed to create nested repo"),
+               },
+               {
+                       imports: []metaImport{
+                               {Prefix: "example.com/user/foo", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                               {Prefix: "example.com/user/foo/bar", VCS: "git", RepoRoot: "https://example.com/repo/target"},
+                       },
+                       path: "example.com",
+                       err:  errors.New("pathologically short path"),
+               },
+       }
+
+       for _, test := range tests {
+               mi, err := matchGoImport(test.imports, test.path)
+               if mi != test.mi {
+                       t.Errorf("unexpected metaImport; got %v, want %v", mi, test.mi)
+               }
+
+               got := err
+               want := test.err
+               if (got == nil) != (want == nil) {
+                       t.Errorf("unexpected error; got %v, want %v", got, want)
+               }
+       }
+}