DRILL-6710: Disallow negative scale for decimal data type

6 files changed, 18 insertions, 7 deletions

diff --git a/exec/java-exec/src/main/java/org/apache/drill/exec/expr/fn/output/DecimalReturnTypeInference.java b/exec/java-exec/src/main/java/org/apache/drill/exec/expr/fn/output/DecimalReturnTypeInference.java
index 442514f79..b30703d7b 100644
--- a/exec/java-exec/src/main/java/org/apache/drill/exec/expr/fn/output/DecimalReturnTypeInference.java
+++ b/exec/java-exec/src/main/java/org/apache/drill/exec/expr/fn/output/DecimalReturnTypeInference.java
@@ -277,7 +277,7 @@ public class DecimalReturnTypeInference {
 
       return TypeProtos.MajorType.newBuilder()
           .setMinorType(attributes.getReturnValue().getType().getMinorType())
-          .setScale(scale)
+          .setScale(Math.max(scale, 0))
           .setPrecision(precision)
           .setMode(mode)
           .build();
diff --git a/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionAddFunction.java b/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionAddFunction.java
index 138f97f63..db00c51a9 100644
--- a/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionAddFunction.java
+++ b/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionAddFunction.java
@@ -31,6 +31,6 @@ public class DecimalScalePrecisionAddFunction extends DrillBaseComputeScalePreci
 
     outputPrecision = (outputScale + maxResultIntegerDigits);
 
-    checkPrecisionRange();
+    adjustScaleAndPrecision();
   }
 }
diff --git a/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionDivideFunction.java b/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionDivideFunction.java
index eb79d44ae..af04f2bc8 100644
--- a/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionDivideFunction.java
+++ b/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionDivideFunction.java
@@ -34,5 +34,6 @@ public class DecimalScalePrecisionDivideFunction extends DrillBaseComputeScalePr
     outputScale = Math.min(outputScale, MAX_NUMERIC_PRECISION - maxResultIntegerDigits);
     outputScale = Math.min(outputScale, DRILL_REL_DATATYPE_SYSTEM.getMaxNumericScale());
     outputPrecision = maxResultIntegerDigits + outputScale;
+    adjustScaleAndPrecision();
   }
 }
diff --git a/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionModFunction.java b/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionModFunction.java
index 6901580eb..9508f3d4e 100644
--- a/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionModFunction.java
+++ b/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionModFunction.java
@@ -38,7 +38,7 @@ public class DecimalScalePrecisionModFunction extends DrillBaseComputeScalePreci
       outputScale = outputPrecision - leftIntegerDigits;
     }
 
-    // Output precision should atleast be greater or equal to the input precision
-    outputPrecision = Math.max(outputPrecision, Math.max(leftPrecision, rightPrecision));
+    // Output precision should at least be greater or equal to the input precision
+    outputPrecision = Math.min(outputPrecision, Math.max(leftPrecision, rightPrecision));
   }
 }
diff --git a/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionMulFunction.java b/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionMulFunction.java
index 2a8b22b9d..6cc553707 100644
--- a/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionMulFunction.java
+++ b/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DecimalScalePrecisionMulFunction.java
@@ -32,10 +32,9 @@ public class DecimalScalePrecisionMulFunction extends DrillBaseComputeScalePreci
   public void computeScalePrecision(int leftPrecision, int leftScale, int rightPrecision, int rightScale) {
     // compute the output scale and precision here
     outputScale = leftScale + rightScale;
-
     outputPrecision = leftPrecision + rightPrecision;
 
-    checkPrecisionRange();
+    adjustScaleAndPrecision();
   }
 }
 
diff --git a/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DrillBaseComputeScalePrecision.java b/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DrillBaseComputeScalePrecision.java
index 1c3c18667..af671e01b 100644
--- a/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DrillBaseComputeScalePrecision.java
+++ b/exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DrillBaseComputeScalePrecision.java
@@ -17,9 +17,14 @@
  */
 package org.apache.drill.exec.planner.types.decimal;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import static org.apache.drill.exec.planner.types.DrillRelDataTypeSystem.DRILL_REL_DATATYPE_SYSTEM;
 
 public abstract class DrillBaseComputeScalePrecision {
+  private static final Logger logger = LoggerFactory.getLogger(DrillBaseComputeScalePrecision.class);
+
   protected final static int MAX_NUMERIC_PRECISION = DRILL_REL_DATATYPE_SYSTEM.getMaxNumericPrecision();
 
   protected int outputScale = 0;
@@ -43,10 +48,16 @@ public abstract class DrillBaseComputeScalePrecision {
    * Cuts down the fractional part if the current precision
    * exceeds the maximum precision range.
    */
-  protected void checkPrecisionRange() {
+  protected void adjustScaleAndPrecision() {
     if (outputPrecision > MAX_NUMERIC_PRECISION) {
       outputScale = outputScale - (outputPrecision - MAX_NUMERIC_PRECISION);
       outputPrecision = MAX_NUMERIC_PRECISION;
     }
+    if (outputScale < 0) {
+      logger.warn("Resulting precision: {} may overflow max allowed precision: {}.\n" +
+          "Forced setting max allowed precision and 0 scale.",
+          MAX_NUMERIC_PRECISION - outputScale, MAX_NUMERIC_PRECISION);
+      outputScale = 0;
+    }
   }
 }