fix(alerting): temp fix for broken AND condition

This should be refactored. lets return condition results instead
of setting new value on the evalContext. The condition execution
should only be able to update its own state.

closes #6449

pkg/services/alerting/conditions/query.go

@@ -42,6 +42,7 @@ func (c *QueryCondition) Eval(context *alerting.EvalContext) {
 	}
 
 	emptySerieCount := 0
+	evalMatchCount := 0
 	for _, series := range seriesList {
 		reducedValue := c.Reducer.Reduce(series)
 		evalMatch := c.Evaluator.Eval(reducedValue)
@@ -58,6 +59,7 @@ func (c *QueryCondition) Eval(context *alerting.EvalContext) {
 		}
 
 		if evalMatch {
+			evalMatchCount++
 			context.EvalMatches = append(context.EvalMatches, &alerting.EvalMatch{
 				Metric: series.Name,
 				Value:  reducedValue.Float64,
@@ -66,7 +68,7 @@ func (c *QueryCondition) Eval(context *alerting.EvalContext) {
 	}
 
 	context.NoDataFound = emptySerieCount == len(seriesList)
-	context.Firing = len(context.EvalMatches) > 0
+	context.Firing = evalMatchCount > 0
 }
 
 func (c *QueryCondition) executeQuery(context *alerting.EvalContext, timeRange *tsdb.TimeRange) (tsdb.TimeSeriesSlice, error) {