fix for -1 in tailLines (#2047)

Author: mattdholloway

pkg/buffer/buffer.go

@@ -32,6 +32,9 @@ const maxLineSize = 10 * 1024 * 1024
 // If the response contains more lines than maxJobLogLines, only the most recent lines are kept.
 // Lines exceeding maxLineSize are truncated with a marker.
 func ProcessResponseAsRingBufferToEnd(httpResp *http.Response, maxJobLogLines int) (string, int, *http.Response, error) {
+	if maxJobLogLines <= 0 {
+		maxJobLogLines = 500
+	}
 	if maxJobLogLines > 100000 {
 		maxJobLogLines = 100000
 	}

pkg/github/actions.go

@@ -702,8 +702,8 @@ For single job logs, provide job_id. For all failed jobs in a run, provide run_i
 			if err != nil {
 				return utils.NewToolResultError(err.Error()), nil, nil
 			}
-			// Default to 500 lines if not specified
-			if tailLines == 0 {
+			// Default to 500 lines if not specified or invalid
+			if tailLines <= 0 {
 				tailLines = 500
 			}