From 19e74da5b20b6362b07fa243842cdc4b9aadae15 Mon Sep 17 00:00:00 2001
From: Callan Barrett <callan@zoocar.org>
Date: Sun, 30 Aug 2026 08:01:20 +0800
Subject: [PATCH] fix(input): reject input macro keys ending in a repeat suffix

parseSuffixRepeat splits a braced input macro token at the last '*'
followed by digits. When the content carries two repeat suffixes the
leftover key name still ends in one, so expandInputMacroExt emitted a
"{name}" token that Command.String() could not write back: re-reading it
stripped the suffix a second time.

"{*1*1}" serialised to "{*1}" and failed to reparse, while "{a*1*2}"
serialised to two "{a*1}" tokens that read back as two "a" tokens.

Reject the ambiguous form at parse time instead of producing a token that
cannot round-trip. Names where '*' is literal ("{ctrl+*}", "{a*b}",
"{a*0}", "{*}") are unaffected.
---
 arguments.go                                  |  6 ++++++
 parser_input_macro_test.go                    | 20 +++++++++++++++++++
 symbols.go                                    |  1 +
 .../fuzz/FuzzCommandString/8b2c3a3ac03788e5   |  2 ++
 4 files changed, 29 insertions(+)
 create mode 100644 testdata/fuzz/FuzzCommandString/8b2c3a3ac03788e5

diff --git a/arguments.go b/arguments.go
index e36595d..22f67be 100644
--- a/arguments.go
+++ b/arguments.go
@@ -268,6 +268,12 @@ func expandInputMacroExt(content string, totalLen *int) ([]string, error) {
 	if name == "" {
 		return nil, ErrInputMacroEmptyKey
 	}
+	// A name that still ends in a repeat suffix (e.g. "{a*1*2}" leaves "a*1")
+	// cannot be written back as "{name}": re-reading would strip the suffix a
+	// second time and yield a different macro. Reject the ambiguous form.
+	if stripped, _, stripErr := parseSuffixRepeat(name); stripErr != nil || stripped != name {
+		return nil, ErrInputMacroAmbiguousKey
+	}
 
 	// Single-rune keys are appended without braces (e.g. "a", "*").
 	// Multi-rune names need braces so ParseKeyCombo recognises them.
diff --git a/parser_input_macro_test.go b/parser_input_macro_test.go
index b5b0161..a06dea0 100644
--- a/parser_input_macro_test.go
+++ b/parser_input_macro_test.go
@@ -122,6 +122,16 @@ func TestInputMacroGrammar(t *testing.T) {
 			input: "**input.keyboard:{a*b}",
 			want:  kbd("{a*b}"),
 		},
+		{
+			name:  "trailing asterisk in combo is literal",
+			input: "**input.keyboard:{ctrl+*}",
+			want:  kbd("{ctrl+*}"),
+		},
+		{
+			name:  "asterisk before zero is literal",
+			input: "**input.keyboard:{a*0}",
+			want:  kbd("{a*0}"),
+		},
 		{
 			name:  "repeat in mixed sequence",
 			input: "**input.keyboard:a{enter*2}b",
@@ -347,6 +357,16 @@ func TestInputMacroCaps(t *testing.T) {
 			input:   "**input.keyboard:{*5}",
 			wantErr: zapscript.ErrInputMacroEmptyKey,
 		},
+		{
+			name:    "key name left with a repeat suffix",
+			input:   "**input.keyboard:{a*1*2}",
+			wantErr: zapscript.ErrInputMacroAmbiguousKey,
+		},
+		{
+			name:    "repeat suffix only key name",
+			input:   "**input.keyboard:{*1*1}",
+			wantErr: zapscript.ErrInputMacroAmbiguousKey,
+		},
 		{
 			name:    "unclosed quoted literal at EOF",
 			input:   `**input.keyboard:{"unclosed`,
diff --git a/symbols.go b/symbols.go
index e844222..6f2af1c 100644
--- a/symbols.go
+++ b/symbols.go
@@ -38,6 +38,7 @@ var (
 	ErrInputMacroRepeatTooLarge = errors.New("input macro repeat count exceeds maximum")
 	ErrInputMacroTooLong        = errors.New("input macro expanded key count exceeds maximum")
 	ErrInputMacroEmptyKey       = errors.New("input macro key name is empty after repeat suffix removal")
+	ErrInputMacroAmbiguousKey   = errors.New("input macro key name ends in a repeat suffix")
 )
 
 const (
diff --git a/testdata/fuzz/FuzzCommandString/8b2c3a3ac03788e5 b/testdata/fuzz/FuzzCommandString/8b2c3a3ac03788e5
new file mode 100644
index 0000000..bea0d20
--- /dev/null
+++ b/testdata/fuzz/FuzzCommandString/8b2c3a3ac03788e5
@@ -0,0 +1,2 @@
+go test fuzz v1
+string("**input.keYBoArd:{*1*1}")