internal/postgres: update GetPathInfo to prefer non-incompatible modules

Updates GetPathInfo to use orderByLatest in the query to prefer
compatible modules.

Updates golang/go#37714

Change-Id: I89fd654c414f860a2f8a327ff9a8fde07fd35120
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/249119
Run-TryBot: Miguel Acero <acero@google.com>
Reviewed-by: Julie Qiu <julie@golang.org>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>

internal/postgres/path.go

@@ -63,12 +63,9 @@ func (db *DB) GetPathInfo(ctx context.Context, path, inModulePath, inVersion str
 		%s
 		WHERE p.path = $1
 		%s
-		ORDER BY
-			m.version_type = 'release' DESC,
-			m.sort_version DESC,
-			m.module_path DESC
+		%s
 		LIMIT 1
-	`, joinStmt, strings.Join(constraints, " "))
+	`, joinStmt, strings.Join(constraints, " "), orderByLatest)
 	err = db.db.QueryRow(ctx, query, args...).Scan(&outModulePath, &outVersion, &isPackage)
 	switch err {
 	case sql.ErrNoRows:

internal/postgres/path_test.go

@@ -31,7 +31,9 @@ func TestGetPathInfo(t *testing.T) {
 		{"m.com", "v1.0.1", "dir/a", false},
 		{"m.com", "v1.1.0", "a/b", false},
 		{"m.com", "v1.2.0-pre", "a", true},
+		{"m.com", "v2.0.0+incompatible", "a", false},
 		{"m.com/a", "v1.1.0", "b", false},
+		{"m.com/b", "v2.0.0+incompatible", "a", true},
 	} {
 		vtype, err := version.ParseType(testModule.version)
 		if err != nil {
@@ -166,6 +168,14 @@ func TestGetPathInfo(t *testing.T) {
 			wantVersion:   "v1.2.0-pre",
 			wantIsPackage: true,
 		},
+		{
+			name:          "incompatible module",
+			path:          "m.com/b",
+			version:       "master",
+			wantModule:    "m.com/b",
+			wantVersion:   "v2.0.0+incompatible",
+			wantIsPackage: false,
+		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			if test.module == "" {