RRDtool can fail to update when sources in Data Template and Graph Template data sources do not match

[ddb4github]

Describe the bug

If a datasource template have many items, and its script return multiple key:value.
And a graph use sone datasource items, not all
After #4988(4dc31e4) commit:

• Cacti will create rrd file with Graph used DS only.
• poller.php will update rrd file with --template with a full field list from script output.

To Reproduce

Steps to reproduce the behavior:

1. Create a DS template with items ds1-ds6

2. Create a Graph template, use ds1-ds5 from above DS Template

3. Create graph instance from above template

4. Run poller.php twice at least

5. See error in terminal: ERROR: unknown DS name 'xxxx'

[TheWitness]

@ddb4github, is this with our without boost?

[TheWitness]

I've done the fix for the non-boost case. Boost is much different than the non-boost case.

[TheWitness]

@ddb4github, this should be resolved now. For the main boost and poller loops, I've made them a bit more common now. There is more work to do here to make the processes more common, but I'll leave that for another day.

[ddb4github]

@ddb4github, this should be resolved now. For the main boost and poller loops, I've made them a bit more common now. There is more work to do here to make the processes more common, but I'll leave that for another day.

@TheWitness test fail, both of 1.2.x and apply-patch-to-1.2.23.
poller.php still show ERROR: unknown DS name and ERROR: tmplt contains more DS definitions than RRD