Never report index.mf at the top of the base as unlisted in check (closes #229)

gen and fetch write the manifest as index.mf at the top of the tree.
check left out only the manifest file it was given, so given a URL, or a
manifest stored elsewhere, it reported that index.mf as not in the
manifest, and --no-extra-files failed a tree fetch had just verified.
check now drops that one report for index.mf at the top of the base
directory. A manifest that lists index.mf still has it checked, and
index.mf in a subdirectory or fetch's leftover .index.mf.tmp are still
reported. The change is in package cli, which owns the default manifest
name; the Checker in package mfer is unchanged.

Model: opus-5-5

internal/cli/entry_test.go

@@ -1190,13 +1190,13 @@ func TestCheckURLManifestWithoutTempDirectory(t *testing.T) {
 	assert.Equal(t, 0, runCLI(opts), "stderr: %s", testStderr(t, opts))
 }
 
-// TestCheckNeverReportsIndexMfAtTopOfBase checks a tree holding index.mf at
+// TestCheckNeverReportsIndexMFAtTopOfBase checks a tree holding index.mf at
 // its top, where gen and fetch write the manifest, against a manifest that
 // does not list it, given by URL and by a path outside the tree: check never
 // reports it, and passes with and without --no-extra-files. index.mf in a
 // subdirectory, and the temp file fetch saves index.mf through, are still
 // reported.
-func TestCheckNeverReportsIndexMfAtTopOfBase(t *testing.T) {
+func TestCheckNeverReportsIndexMFAtTopOfBase(t *testing.T) {
 	t.Parallel()
 
 	files := map[string][]byte{testFileTxt: []byte("hello")}
@@ -1239,7 +1239,7 @@ func TestCheckNeverReportsIndexMfAtTopOfBase(t *testing.T) {
 			assert.NotContains(t, stderr, "EXTRA: "+defaultManifestName)
 
 			reported := []string{
-				testSubdir + "/" + defaultManifestName,
+				testSubdirManifest,
 				tempPathFor(defaultManifestName),
 			}
 
@@ -1261,10 +1261,10 @@ func TestCheckNeverReportsIndexMfAtTopOfBase(t *testing.T) {
 	}
 }
 
-// TestCheckChecksListedIndexMf checks a tree against a manifest that lists
+// TestCheckChecksListedIndexMF checks a tree against a manifest that lists
 // index.mf at the top of the tree, where that file has changed since: check
 // reports it like any other changed file.
-func TestCheckChecksListedIndexMf(t *testing.T) {
+func TestCheckChecksListedIndexMF(t *testing.T) {
 	t.Parallel()
 
 	manifestPath := filepath.Join(t.TempDir(), "other.mf")
@@ -1331,11 +1331,11 @@ func TestCheckWithUnlistableDirectory(t *testing.T) {
 	assert.Contains(t, testStderr(t, opts), "unlisted.txt")
 }
 
-// TestCheckReportsUnreadableIndexMfAtTopOfBase has a directory named
+// TestCheckReportsUnreadableIndexMFAtTopOfBase has a directory named
 // index.mf at the top of the base that cannot be listed. check leaves out
 // only the report that index.mf is not in the manifest, so it reports the
 // error and fails under --no-extra-files.
-func TestCheckReportsUnreadableIndexMfAtTopOfBase(t *testing.T) {
+func TestCheckReportsUnreadableIndexMFAtTopOfBase(t *testing.T) {
 	t.Parallel()
 
 	unreadable := filepath.Join(testDir, defaultManifestName)