fix: --glob panics on a pattern gobwas/glob rejects

internal/glob/glob.go

@@ -12,19 +12,22 @@ import (
 type Glob struct {
 	Pattern string
 	Negated bool
+
+	// compiled is the `gobwas/glob` form of Pattern, built once by NewGlob.
+	// It's nil for a `**` pattern, which doublestar matches instead.
+	compiled glob.Glob
 }
 
 // Match returns whether or not the Glob g matches the string query.
 func (g Glob) Match(query string) bool {
 	q := filepath.ToSlash(query)
 
-	if strings.Contains(g.Pattern, "**") {
+	if g.compiled == nil {
 		matched, _ := doublestar.Match(g.Pattern, q)
 		return matched != g.Negated
 	}
 
-	p := glob.MustCompile(g.Pattern)
-	return p.Match(q) != g.Negated
+	return g.compiled.Match(q) != g.Negated
 }
 
 // MatchAny returns whether or not the Glob g matches any of the strings in
@@ -49,7 +52,18 @@ func NewGlob(pat string) (Glob, error) {
 	if err != nil {
 		return Glob{}, err
 	}
-	return Glob{Pattern: pat, Negated: negate}, nil
+
+	if strings.Contains(pat, "**") {
+		return Glob{Pattern: pat, Negated: negate}, nil
+	}
+
+	// doublestar accepts patterns gobwas/glob rejects, and Match used to
+	// compile there with MustCompile -- so `--glob='[a-]*'` panicked mid-walk.
+	compiled, err := glob.Compile(pat)
+	if err != nil {
+		return Glob{}, err
+	}
+	return Glob{Pattern: pat, Negated: negate, compiled: compiled}, nil
 }
 
 // Compile is a wrapper around NewGlobal for backwards compatibility.

internal/glob/glob_test.go

@@ -32,6 +32,20 @@ var globTests = []struct {
 	},
 }
 
+// Patterns doublestar accepts and gobwas/glob rejects. NewGlob has to report
+// them, since Match can't: it used to compile with MustCompile and panicked
+// partway through the walk.
+var invalidGlobs = []string{`[a-]`, `[a-b-c]`}
+
+func TestInvalidGlob(t *testing.T) {
+	for _, pat := range invalidGlobs {
+		g, err := NewGlob(pat)
+		if err == nil {
+			t.Errorf("%s: expected an error, got %+v", pat, g)
+		}
+	}
+}
+
 func TestGlob(t *testing.T) {
 	for _, tt := range globTests {
 		g, _ := NewGlob(tt.pattern)

testdata/e2e/config-flags.yaml

@@ -94,6 +94,14 @@ cases:
       - py
     requires: asciidoctor, dita, rst2html, xsltproc
 
+  - name: glob-invalid
+    about: "a pattern gobwas/glob rejects used to panic mid-walk"
+    dir: ../glob
+    args: "--glob=[a-]* ."
+    exit: 2
+    want: |
+      expected close range character
+
   - name: no-config-found
     dir: ../../../..
     args: .