7 files changed, 75 insertions, 0 deletions

diff --git a/cmd/krino/check.go b/cmd/krino/check.go
index d4aee01..ec08672 100644
--- a/cmd/krino/check.go
+++ b/cmd/krino/check.go
@@ -22,6 +22,9 @@ func cmdCheck(g *globals, args []string, stdout, stderr io.Writer) int {
 	if g.minAgeSet {
 		return usageError(stderr, "--min-age applies only to sorting and explain")
 	}
+	if code, refused := refuseUnusedFlags(g, stderr, "check", false); refused {
+		return code
+	}
 	e, errs := engine.Load(mainFile(g), fs.Args()...)
 	if len(errs) > 0 {
 		printDiags(stderr, errs)
diff --git a/cmd/krino/common.go b/cmd/krino/common.go
index 15c32f6..5b6869a 100644
--- a/cmd/krino/common.go
+++ b/cmd/krino/common.go
@@ -33,6 +33,30 @@ func minAgeOverride(g *globals) (d time.Duration, set bool, err error) {
 	return d, true, nil
 }
 
+// refuseUnusedFlags refuses the global flags a command does not use -
+// -y and -n unless usesYesDry, and --json and -v - instead of silently
+// ignoring them, so "krino -n new ...", meant as a preview, cannot write
+// config (re-review cli F4). It reports whether it refused.
+func refuseUnusedFlags(g *globals, stderr io.Writer, cmd string, usesYesDry bool) (int, bool) {
+	var given []string
+	if !usesYesDry && g.yes {
+		given = append(given, "-y")
+	}
+	if !usesYesDry && g.dry {
+		given = append(given, "-n")
+	}
+	if g.json {
+		given = append(given, "--json")
+	}
+	if g.verbose {
+		given = append(given, "-v")
+	}
+	if len(given) == 0 {
+		return 0, false
+	}
+	return usageError(stderr, fmt.Sprintf("%s does not take %s", cmd, strings.Join(given, ", "))), true
+}
+
 // cacheDir is where every directory's keyword cache lives (spec §6.1).
 func cacheDir() string {
 	return filepath.Join(xdg.CacheHome(), "krino")
diff --git a/cmd/krino/history_test.go b/cmd/krino/history_test.go
index fce38ad..6d8c1e4 100644
--- a/cmd/krino/history_test.go
+++ b/cmd/krino/history_test.go
@@ -516,3 +516,39 @@ func TestMinAgeRejectedOutsideSortAndExplain(t *testing.T) {
 		t.Errorf("-n --min-age 0: exit %d %s", code, errOut)
 	}
 }
+
+// TestIgnoredGlobalFlagsAreRefused: a global flag a command does not use is
+// refused instead of silently ignored, so "krino -n new ..." or "krino -n
+// init" - meant as a preview - cannot write config (re-review cli F4).
+func TestIgnoredGlobalFlagsAreRefused(t *testing.T) {
+	h := home(t)
+	if code, _, errOut := runCLI(t, "-n", "init"); code != 2 || !strings.Contains(errOut, "-n") {
+		t.Errorf("-n init: exit %d %q", code, errOut)
+	}
+	if _, err := os.Stat(filepath.Join(h, ".config", "krino", "krino.conf")); !os.IsNotExist(err) {
+		t.Fatalf("-n init wrote the config: %v", err)
+	}
+	if code, _, errOut := runCLI(t, "init"); code != 0 {
+		t.Fatal(errOut)
+	}
+	dl := filepath.Join(h, "dl")
+	os.MkdirAll(dl, 0o755)
+	for _, args := range [][]string{
+		{"-n", "new", "dl", dl},
+		{"-y", "check"},
+		{"--json", "log"},
+		{"-v", "log"},
+		{"--json", "undo", "-n"},
+		{"-v", "undo", "-n"},
+	} {
+		if code, _, errOut := runCLI(t, args...); code != 2 || !strings.Contains(errOut, "does not take") {
+			t.Errorf("krino %q: exit %d, stderr %q; want 2, refused", args, code, errOut)
+		}
+	}
+	if _, err := os.Stat(filepath.Join(h, ".config", "krino", "dirs", "dl.conf")); !os.IsNotExist(err) {
+		t.Errorf("-n new wrote a directory file: %v", err)
+	}
+	if code, _, errOut := runCLI(t, "log", "-n", "3"); code != 0 {
+		t.Errorf("log -n 3 (its own count flag) was refused: %d %q", code, errOut)
+	}
+}
diff --git a/cmd/krino/init.go b/cmd/krino/init.go
index 1806ab9..6feb6d0 100644
--- a/cmd/krino/init.go
+++ b/cmd/krino/init.go
@@ -22,6 +22,9 @@ func cmdInit(g *globals, args []string, stdout, stderr io.Writer) int {
 	if g.minAgeSet {
 		return usageError(stderr, "--min-age applies only to sorting and explain")
 	}
+	if code, refused := refuseUnusedFlags(g, stderr, "init", false); refused {
+		return code
+	}
 	if fs.NArg() != 0 {
 		return usageError(stderr, "init takes no arguments")
 	}
diff --git a/cmd/krino/log.go b/cmd/krino/log.go
index 2394ec2..903f8e8 100644
--- a/cmd/krino/log.go
+++ b/cmd/krino/log.go
@@ -57,6 +57,9 @@ func cmdLog(g *globals, args []string, stdout, stderr io.Writer) int {
 	if g.minAgeSet {
 		return usageError(stderr, "--min-age applies only to sorting and explain")
 	}
+	if code, refused := refuseUnusedFlags(g, stderr, "log", false); refused {
+		return code
+	}
 	if fs.NArg() > 0 {
 		return usageError(stderr, "usage: krino log [-n N]")
 	}
diff --git a/cmd/krino/new.go b/cmd/krino/new.go
index ced9dc2..0390e82 100644
--- a/cmd/krino/new.go
+++ b/cmd/krino/new.go
@@ -21,6 +21,9 @@ func cmdNew(g *globals, args []string, stdout, stderr io.Writer) int {
 	if g.minAgeSet {
 		return usageError(stderr, "--min-age applies only to sorting and explain")
 	}
+	if code, refused := refuseUnusedFlags(g, stderr, "new", false); refused {
+		return code
+	}
 	if fs.NArg() != 2 {
 		return usageError(stderr, "usage: krino new NAME PATH")
 	}
diff --git a/cmd/krino/undo.go b/cmd/krino/undo.go
index 4cefc82..1b5e6ae 100644
--- a/cmd/krino/undo.go
+++ b/cmd/krino/undo.go
@@ -50,6 +50,9 @@ func cmdUndo(g *globals, args []string, stdout, stderr io.Writer) int {
 	if g.minAgeSet {
 		return usageError(stderr, "--min-age applies only to sorting and explain")
 	}
+	if code, refused := refuseUnusedFlags(g, stderr, "undo", true); refused {
+		return code
+	}
 	if g.yes && g.dry {
 		return usageError(stderr, "-y and -n cannot be used together")
 	}