input/vcd: abort VCD import when timestamp counts backwards

The VCD specification requests that timestamps will strictly increase as
one advances through the file. Add another check where the previous
implementation resulted in a tight loop and made the application stall.
Do print an error message and abort file processing in that case.

This fixes bug #1250.

diff --git a/src/input/vcd.c b/src/input/vcd.c
index 7614ba68a6f7bc192dab8c4f85cddccb91c34954..b9e9497dc8baf07b65370329179a615d2c175531 100644 (file)
--- a/src/input/vcd.c
+++ b/src/input/vcd.c
@@ -408,6 +408,10 @@ static void parse_contents(const struct sr_input *in, char *data)
                                inc->prev_timestamp = inc->skip;
                        } else if (timestamp == inc->prev_timestamp) {
                                /* Ignore repeated timestamps (e.g. sigrok outputs these) */
+                       } else if (timestamp < inc->prev_timestamp) {
+                               sr_err("Invalid timestamp: %" PRIu64 " (smaller than previous timestamp).", timestamp);
+                               inc->skip_until_end = TRUE;
+                               break;
                        } else {
                                if (inc->compress != 0 && timestamp - inc->prev_timestamp > inc->compress) {
                                        /* Compress long idle periods */