Additinal fix for #8180: Make sure trace session slots will not break use counter (#8192)

* Count dead storages carefully

* Better class to track dead process

Also correct the description

---------

Co-authored-by: Artyom Abakumov <artyom.abakumov@red-soft.ru>

Author: Noremos

src/jrd/trace/TraceConfigStorage.cpp

@@ -470,15 +470,20 @@ void ConfigStorage::compact()
 	ULONG check_used, check_size;
 	check_used = check_size = sizeof(TraceCSHeader);
 
+	// Track undeleted slots from dead processes
+	Firebird::SortedArray<ULONG, InlineStorage<ULONG, 16>> deadProcesses;
+
 	// collect used slots, sort them by offset
 	for (TraceCSHeader::Slot* slot = header->slots; slot < header->slots + header->slots_cnt; slot++)
 	{
 		if (slot->used && slot->ses_pid != pid &&
 			((slot->ses_flags & trs_system) == 0) && // System sessions are shared for multiple connections so they may live without the original process
 			!ISC_check_process_existence(slot->ses_pid))
 		{
-			fb_assert(header->cnt_uses != 0);
-			header->cnt_uses--; // Process that created trace session disappeared, count it out
+			// A SUPER server may shut down, but its Storage shared memory continues to live due to an embedded user session.
+			// The process might allocate multiple slots, so count them carefully.
+			deadProcesses.add(slot->ses_pid);
+
 			markDeleted(slot);
 		}
 
@@ -491,6 +496,11 @@ void ConfigStorage::compact()
 		data.add(item);
 	}
 
+	// Process that created storages disappeared, count it out
+	fb_assert(header->cnt_uses > deadProcesses.getCount());
+	header->cnt_uses -= deadProcesses.getCount();
+	deadProcesses.clear();
+
 	fb_assert(check_used == header->mem_used);
 	fb_assert(check_size == header->mem_offset);