Java: Restrict attention to integral types in IntMultToLong.

change-notes/1.20/analysis-java.md

@@ -14,6 +14,7 @@
 
 | **Query**                  | **Expected impact**    | **Change**                                                       |
 |----------------------------|------------------------|------------------------------------------------------------------|
+| Result of multiplication cast to wider type (`java/integer-multiplication-cast-to-long`) | Fewer results | Results involving conversions to `float` or `double` are no longer reported, as they were almost exclusively false positives. |
 
 ## Changes to QL libraries
 

java/ql/src/Likely Bugs/Arithmetic/IntMultToLong.ql

@@ -47,6 +47,8 @@ where
   e.getType() = sourceType and
   c.getConversionTarget() = destType and
   destType.widerThan(sourceType) and
+  // restrict attention to integral types
+  destType instanceof IntegralType and
   // not a trivial conversion
   not c.isTrivial() and
   // not an explicit conversion, which is probably intended by a user