SERVER-30803 Better error message for invalid result with $inc/$mul.

This adds back a check that got lost in the translation from
modifier_inc to ArithmeticNode.

1 files changed, 12 insertions, 6 deletions

diff --git a/src/mongo/db/update/arithmetic_node.cpp b/src/mongo/db/update/arithmetic_node.cpp
index 49dfc9165e6..c5b7a3373f7 100644
--- a/src/mongo/db/update/arithmetic_node.cpp
+++ b/src/mongo/db/update/arithmetic_node.cpp
@@ -76,12 +76,11 @@ Status ArithmeticNode::init(BSONElement modExpr, const CollatorInterface* collat
 ModifierNode::ModifyResult ArithmeticNode::updateExistingElement(
     mutablebson::Element* element, std::shared_ptr<FieldRef> elementPath) const {
     if (!element->isNumeric()) {
-        mutablebson::Element idElem =
-            mutablebson::findFirstChildNamed(element->getDocument().root(), "_id");
+        auto idElem = mutablebson::findFirstChildNamed(element->getDocument().root(), "_id");
         uasserted(ErrorCodes::TypeMismatch,
                   str::stream() << "Cannot apply " << getModifierNameForOp(_op)
                                 << " to a value of non-numeric type. {"
-                                << idElem.toString()
+                                << (idElem.ok() ? idElem.toString() : "no id")
                                 << "} has the field '"
                                 << element->getFieldName()
                                 << "' of non-numeric type "
@@ -103,10 +102,17 @@ ModifierNode::ModifyResult ArithmeticNode::updateExistingElement(
     // if the found element is in a deserialized state, we can't do that.
     if (element->getValue().ok() && valueToSet.isIdentical(originalValue)) {
         return ModifyResult::kNoOp;
+    } else if (!valueToSet.isValid()) {
+        auto idElem = mutablebson::findFirstChildNamed(element->getDocument().root(), "_id");
+        uasserted(ErrorCodes::BadValue,
+                  str::stream() << "Failed to apply " << getModifierNameForOp(_op)
+                                << " operations to current value ("
+                                << originalValue.debugString()
+                                << ") for document {"
+                                << (idElem.ok() ? idElem.toString() : "no id")
+                                << "}");
     } else {
-
-        // This can fail if 'valueToSet' is not representable as a 64-bit integer.
-        uassertStatusOK(element->setValueSafeNum(valueToSet));
+        invariantOK(element->setValueSafeNum(valueToSet));
         return ModifyResult::kNormalUpdate;
     }
 }