logging: int-uint comparsion causes false assert & epic hang

[emillindq]

Describe the bug
This piece of code

zephyr/subsys/logging/log_mgmt.c

Lines 185 to 202 in 963d05b

	uint32_t log_filter_get(struct log_backend const *const backend,
	uint32_t domain_id, int16_t source_id, bool runtime)
	{
	__ASSERT_NO_MSG(source_id < z_log_sources_count());
	if (IS_ENABLED(CONFIG_LOG_RUNTIME_FILTERING) && runtime) {
	if (source_id < 0) {
	return LOG_LEVEL_DBG;
	}
	uint32_t *filters = z_log_dynamic_filters_get(source_id);
	return LOG_FILTER_SLOT_GET(filters,
	log_backend_id_get(backend));
	}
	return log_compiled_level_get(source_id);
	}

source_id is int16_t and can take the value -1 according to the if statement. Now, z_log_sources_count() returns uint32_t which causes a classical int-uint comparison causing the -1 to become UINT32_MAX when converted. This is what happened for me anyways.
This in turn will trigger an assert, which in the assert will also be -1, which somehow causes the debugger to loose connection with target.

I want to make a PR for this, but my question for this is how to solve this in the best way? Typecase the z_log_sources_count() to int before comparing?

[emillindq]

Obviously this only shows itself if building with ASSERTS active and some special cases, for example (I think) when redirecting PRINTK to LOG subsystem in which I think source_id is -1