Fix set with duplicate elements causes sdiff to hang (#11530)

This payload produces a set with duplicate elements (listpack encoding):
```
restore _key 0 "\x14\x25\x25\x00\x00\x00\x0A\x00\x06\x01\x82\x5F\x35\x03\x04\x01\x82\x5F\x31\x03\x82\x5F\x33\x03\x00\x01\x82\x5F\x39\x03\x82\x5F\x33\x03\x08\x01\x02\x01\xFF\x0B\x00\x31\xBE\x7D\x41\x01\x03\x5B\xEC"

smembers key
1) "6"
2) "_5"
3) "4"
4) "_1"
5) "_3"  ---> dup
6) "0"
7) "_9"
8) "_3"  ---> dup
9) "8"
10) "2"
```

This kind of sets will cause SDIFF to hang, SDIFF generated a broken
protocol and left the client hung. (Expected ten elements, but only
got nine elements due to the duplication.)

If we set `sanitize-dump-payload` to yes, we will be able to find
the duplicate elements and report "ERR Bad data format".

Discovered and discussed in #11290.

This PR also improve prints when corrupt-dump-fuzzer hangs, it will
print the cmds and the payload, an example like:
```
Testing integration/corrupt-dump-fuzzer
[TIMEOUT]: clients state report follows.
sock6 => (SPAWNED SERVER) pid:28884
Killing still running Redis server 28884
commands caused test to hang:
SDIFF __key 
payload that caused test to hang: "\x14\balabala"
```

Co-authored-by: Oran Agra <oran@redislabs.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/tests/support/util.tcl b/tests/support/util.tcl
index 22774868c..b2c9bdf7a 100644
--- a/tests/support/util.tcl
+++ b/tests/support/util.tcl
@@ -730,13 +730,20 @@ proc generate_fuzzy_traffic_on_key {key duration} {
         } else {
             set err [format "%s" $err] ;# convert to string for pattern matching
             if {[string match "*SIGTERM*" $err]} {
-                puts "command caused test to hang? $cmd"
-                exit 1
+                puts "commands caused test to hang:"
+                foreach cmd $sent {
+                    foreach arg $cmd {
+                        puts -nonewline "[string2printable $arg] "
+                    }
+                    puts ""
+                }
+                # Re-raise, let handler up the stack take care of this.
+                error $err $::errorInfo
             }
         }
     }
 
-    # print stats so that we know if we managed to generate commands that actually made senes
+    # print stats so that we know if we managed to generate commands that actually made sense
     #if {$::verbose} {
     #    set count [llength $sent]
     #    puts "Fuzzy traffic sent: $count, succeeded: $succeeded"