More lenient with rustfmt warnings. Fixes RustDT#144

documentation/ChangeLog.md

@@ -5,6 +5,7 @@
  #TODO
  * Added syntax coloring support for `?` operator.
  * Invoking a build operation for a project now immediately cancels the pending build operation for that project, if any.
+ * More lenient with `rustfmt` exit code 3, don't treat those warnings as a failure. (#144)
 
 ### 0.7.0
  * Added support for Rust 1.12 new error message format. (#130)

plugin_tooling/src/com/github/rustdt/tooling/ops/RustFmtOperation.java

@@ -58,9 +58,15 @@ public String executeToolOperation(IOperationMonitor om)
 	protected String handleResult(ExternalProcessResult result) throws CommonException, OperationSoftFailure {
 		int exitValue = result.exitValue;
 
+		if(exitValue == 3) {
+			// Some warnings were generated, but `rustfmt` did complete, so use the result
+			// TODO: we could display the warnings in a non-modal notification UI
+			// or even as warning markers?
+		} else 
 		if(exitValue != 0) {
-			throw new OperationSoftFailure("`rustfmt` did not complete successfully, exit code: " + exitValue + "\n" + 
-					result.getStdErrBytes().toUtf8String());
+			String msg = "`rustfmt` did not complete successfully, exit code: " + exitValue + "\n" + 
+					result.getStdErrBytes().toUtf8String();
+			throw new OperationSoftFailure(msg);
 		}
 
 		// formatted file is in stdout