Yes, I agree that failed builds should always be excluded from builds. The Problem is, that currently there are only two option:
1) Don't run the Warningsblugin on failed build (so disable the "always run this plugin" option in the advanced options
2) Enable the Option and let it run regardles of the failure of the build.
With Option 1 everything with the trendgraph/new warnings is okay, except that when a build fails you manually have to scan the console output to see what is going wrong, thats why I use option 2, this creates "High Priority Warnings" for compile errors that could be easily reviewed (and fixed of course .
The problem with option 1 is the following:
Assume a build with 100 Sourcefiles each one generates a warning so if everything is fine it says 100 warnings, 0 new, 0 fixed.
When the build fails, lets say after the 20th file it says 21 Warnings (20 'normal' one 'high') 1 new, 80 fixed.
When the build gets okay again it compiles all files and say 100 Warnings, 80 new 1 fixed.
The Trendgraph then has a "peak" down and up for this broken build als well as the new/fixed ration is missleading.
So what would be nice is a combination of 1+2 which parses (and shows) the warnings on a failed so they could be reviewed, but behaves like this build never happens on the trendgraph/difference calculation.
I hope this makes things a little more clean, if prefereable I can attatch some screenshots but they would be in german if thats okay.