fix: close the review nits in the write path, query path and tests

Remove the temp file on every writeJSON failure path, not just the write
and close ones. A failed rename left the temp behind with no cleanup.

Surface the list path's unmarshal error instead of printing null with exit
0, and make a non-positive history limit print an empty array rather than
falling through to the whole ring.

Assert the evicted item actually lands in the history ring, so the "files
to history" half of eviction is covered rather than just its signal.

Add the missing README License section beside the GPLv2 text and headers.

1 files changed, 8 insertions, 1 deletions

diff --git a/cmd/notifyctl/main.go b/cmd/notifyctl/main.go
index ca1db86..e0875e7 100644
--- a/cmd/notifyctl/main.go
+++ b/cmd/notifyctl/main.go
@@ -52,6 +52,10 @@ func main() {
 			}
 			limit = n
 		}
+		if limit < 1 {
+			fmt.Println("[]")
+			return
+		}
 		printFile("history.json", limit)
 	case "close":
 		need(3)
@@ -106,7 +110,10 @@ func printFile(name string, limit int) {
 		return
 	}
 	var pretty any
-	json.Unmarshal(data, &pretty)
+	if err := json.Unmarshal(data, &pretty); err != nil {
+		fmt.Fprintf(os.Stderr, "notifyctl: %v\n", err)
+		os.Exit(1)
+	}
 	out, _ := json.MarshalIndent(pretty, "", "  ")
 	fmt.Println(string(out))
 }