internal/source: support git.apache.org

git.apache.org repos are hosted on GitHub. The final ".git" in the module
path throws off the meta-tag matcher, so handle it specially.

Change-Id: I57a8da4d4a000f0acd72945b6efa4439579e6518
Reviewed-on: https://team-review.git.corp.google.com/c/golang/discovery/+/572877
CI-Result: Cloud Build <devtools-proctor-result-processor@system.gserviceaccount.com>
Reviewed-by: Julie Qiu <julieqiu@google.com>

internal/source/source.go

@@ -161,6 +161,13 @@ func matchStatic(moduleOrRepoPath string) (repo, relativeModulePath string, _ ur
 				break
 			}
 		}
+		// Special case: git.apache.org has a go-import tag that points to
+		// github.com/apache, but it's not quite right (the repo prefix is
+		// missing a ".git"), so handle it here.
+		const apacheDomain = "git.apache.org/"
+		if strings.HasPrefix(repo, apacheDomain) {
+			repo = strings.Replace(repo, apacheDomain, "github.com/apache/", 1)
+		}
 		relativeModulePath = strings.TrimPrefix(moduleOrRepoPath, matches[0])
 		relativeModulePath = strings.TrimPrefix(relativeModulePath, "/")
 		return repo, relativeModulePath, pat.templates, nil
@@ -316,13 +323,17 @@ var patterns = []struct {
 	// a ".git" repo suffix in an import path. If matching a repo URL from a meta tag,
 	// there is no ".git".
 	{
-		regexp.MustCompile(`^(?P<repo>[^.]+\.googlesource.com/[^.]+)(\.git|$)`),
+		regexp.MustCompile(`^(?P<repo>[^.]+\.googlesource\.com/[^.]+)(\.git|$)`),
 		urlTemplates{
 			directory: "{repo}/+/{commit}/{dir}",
 			file:      "{repo}/+/{commit}/{file}",
 			line:      "{repo}/+/{commit}/{file}#{line}",
 		},
 	},
+	{
+		regexp.MustCompile(`^(?P<repo>git\.apache\.org/[^.]+)(\.git|$)`),
+		githubURLTemplates,
+	},
 	// General syntax for the go command. We can extract the repo and directory, but
 	// we don't know the URL templates.
 	// Must be last in this list.

internal/source/source_test.go

@@ -111,6 +111,15 @@ func TestModuleInfo(t *testing.T) {
 			"https://go.googlesource.com/image/+/69e4b8554b2a/math/fixed/fixed.go",
 			"https://go.googlesource.com/image/+/69e4b8554b2a/math/fixed/fixed.go#1",
 		},
+		{
+			"git.apache.org",
+			"git.apache.org/thrift.git", "v0.12.0", "lib/go/thrift/client.go",
+
+			"https://github.com/apache/thrift",
+			"https://github.com/apache/thrift/tree/v0.12.0",
+			"https://github.com/apache/thrift/blob/v0.12.0/lib/go/thrift/client.go",
+			"https://github.com/apache/thrift/blob/v0.12.0/lib/go/thrift/client.go#L1",
+		},
 		{
 			"vanity for github",
 			"cloud.google.com/go/spanner", "v1.0.0", "doc.go",