BUG FIX: Respect options(warn=2) on workers [#794]

Author: HenrikBengtsson

DESCRIPTION

@@ -1,5 +1,5 @@
 Package: future
-Version: 1.49.0-9021
+Version: 1.49.0-9022
 Title: Unified Parallel and Distributed Processing in R for Everyone
 Depends:
     R (>= 3.2.0)

NEWS.md

@@ -12,9 +12,16 @@
    graphics devices explicitly (e.g. `pdf()` or `png()`) before
    plotting. Alternatively, explicitly set R option `device` inside
    the future expression.
-
+   
 ## Bug Fixes
 
+ * Setting `options(warn = 2)` on a parallel worker was ignored -
+   warnings were not escalated to errors on the worker, and was
+   instead relayed as-is in the parent R session, unless `options(warn
+   = 2)` was also set in the parent. Now `options(warn = 2)` on a
+   worker causes warnings to be escalated immediately to errors on the
+   worker, which therefore also terminates the future.
+
  * The `multicore` backend did not relay `immediateCondition`:s in a
    near-live fashion, but only when the results of the futures where
    collected.

R/backend_api-evalFuture.R

@@ -1044,6 +1044,13 @@ evalFutureInternal <- function(data) {
                      !is.null(conditionClasses) &&
                      inherits(cond, conditionClasses)
                     ) {
+
+            ## SPECIAL CASE: If a warnings and option 'warn' is >= 2 on the
+            ## worker, then let it escalate to an error here on the worker
+            if (inherits(cond, "warning") && getOption("warn") >= 2L) {
+              return()
+            }
+            
             ## Relay 'immediateCondition' conditions immediately?
             ## If so, then do not muffle it and flag it as signaled
             ## already here.
@@ -1058,6 +1065,12 @@ evalFutureInternal <- function(data) {
             }
           } else {
             if (!split && !is.null(conditionClasses)) {
+              ## SPECIAL CASE: If a warnings and option 'warn' is >= 2 on the
+              ## worker, then let it escalate to an error here on the worker
+              if (inherits(cond, "warning") && getOption("warn") >= 2L) {
+                return()
+              }
+            
               ## Muffle all non-captured conditions
               muffleCondition(cond, pattern = muffleInclude)
             }