Fix panic when git config contains a key without a value

main.go

@@ -838,16 +838,7 @@ func main() {
 		log.V(0).Info("unexpected stderr reading git config", "stdout", stdout, "stderr", stderr)
 		os.Exit(1)
 	} else {
-		cfgs := strings.Split(stdout, string(rune(0)))
-		kvs := funcr.PseudoStruct{} // like a map but ordered
-		for _, cfg := range cfgs {
-			if cfg == "" {
-				continue
-			}
-			parts := strings.SplitN(cfg, "\n", 2) // any additional newlines are part of the value
-			kvs = append(kvs, parts[0], parts[1])
-		}
-		log.V(0).Info("git config", "configs", kvs)
+		log.V(0).Info("git config", "configs", parseGitConfigList(stdout))
 	}
 
 	// The scope of the initialization context ends here, so we call cancel to release resources associated with it.
@@ -2324,6 +2315,26 @@ type keyVal struct {
 	val string
 }
 
+// parseGitConfigList parses the output of `git config list -z`.  A key with no
+// value (e.g. a bare `key` line, which git treats as boolean true) is printed
+// without a newline, and is reported with a nil value.
+func parseGitConfigList(stdout string) funcr.PseudoStruct {
+	cfgs := strings.Split(stdout, string(rune(0)))
+	kvs := funcr.PseudoStruct{} // like a map but ordered
+	for _, cfg := range cfgs {
+		if cfg == "" {
+			continue
+		}
+		parts := strings.SplitN(cfg, "\n", 2) // any additional newlines are part of the value
+		if len(parts) == 1 {
+			kvs = append(kvs, parts[0], nil)
+			continue
+		}
+		kvs = append(kvs, parts[0], parts[1])
+	}
+	return kvs
+}
+
 func parseGitConfigs(configsFlag string) ([]keyVal, error) {
 	// Use a channel as a FIFO.  We don't expect the input strings to be very
 	// large, so this simple model should suffice.

main_test.go

@@ -24,6 +24,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/go-logr/logr/funcr"
 	"go.uber.org/goleak"
 )
 
@@ -248,6 +249,53 @@ func TestParseGitConfigs(t *testing.T) {
 	}
 }
 
+func TestParseGitConfigList(t *testing.T) {
+	cases := []struct {
+		name   string
+		input  string
+		expect funcr.PseudoStruct
+	}{{
+		name:   "empty",
+		input:  "",
+		expect: funcr.PseudoStruct{},
+	}, {
+		name:   "one-pair",
+		input:  "k\nv\x00",
+		expect: funcr.PseudoStruct{"k", "v"},
+	}, {
+		name:   "no-trailing-nul",
+		input:  "k\nv",
+		expect: funcr.PseudoStruct{"k", "v"},
+	}, {
+		name:   "empty-value",
+		input:  "k\n\x00",
+		expect: funcr.PseudoStruct{"k", ""},
+	}, {
+		name:   "multi-line-value",
+		input:  "k\nline1\nline2\x00",
+		expect: funcr.PseudoStruct{"k", "line1\nline2"},
+	}, {
+		// `git config list -z` prints a key with no value (e.g. a bare `key`
+		// line, which git treats as boolean true) without a newline.
+		name:   "no-value",
+		input:  "k\x00",
+		expect: funcr.PseudoStruct{"k", nil},
+	}, {
+		name:   "multiple",
+		input:  "core.bare\nfalse\x00demo.bare\x00demo.empty\n\x00demo.multi\nline1\nline2\x00",
+		expect: funcr.PseudoStruct{"core.bare", "false", "demo.bare", nil, "demo.empty", "", "demo.multi", "line1\nline2"},
+	}}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			kvs := parseGitConfigList(tc.input)
+			if !reflect.DeepEqual(kvs, tc.expect) {
+				t.Errorf("bad result:\n\texpected: %#v\n\t     got: %#v", tc.expect, kvs)
+			}
+		})
+	}
+}
+
 func TestDirIsEmpty(t *testing.T) {
 	root := absPath(t.TempDir())