ruby: ad 'quality' tag to 'rb/unused-parameter'

ruby/ql/lib/codeql/ruby/controlflow/internal/Completion.qll

@@ -69,6 +69,9 @@ private predicate completionIsValidForStmt(AstNode n, Completion c) {
   or
   n instanceof ReturnStmt and
   c = TReturnCompletion()
+  or
+  n instanceof RetryStmt and
+  c = TRetryCompletion()
 }
 
 private AstNode getARescuableBodyChild() {

ruby/ql/lib/codeql/ruby/controlflow/internal/ControlFlowGraphImpl.qll

@@ -1319,6 +1319,11 @@ module Trees {
       last(super.getBody(), pred, c) and
       c instanceof NormalCompletion and
       succ = this
+      or
+      pred = super.getBody().getAStmt().getAChild*() and
+      pred instanceof RetryStmt and
+      c instanceof RetryCompletion and
+      exists(BodyStmtTree stmt | this = stmt.getARescue() | first(stmt, succ))
     }
   }
 

ruby/ql/src/queries/variables/UninitializedLocal.ql

@@ -18,6 +18,10 @@ class RelevantLocalVariableReadAccess extends LocalVariableReadAccess {
     not exists(MethodCall c |
       c.getReceiver() = this and
       c.getMethodName() = "nil?"
+    ) and
+    not exists(BinaryOperation b |
+      b.getLeftOperand() = this and
+      b.getOperator() = "||"
     )
   }
 }

ruby/ql/src/queries/variables/UnusedParameter.ql

@@ -7,6 +7,7 @@
  * @id rb/unused-parameter
  * @tags maintainability
  *       external/cwe/cwe-563
+ *       quality
  * @precision low
  */
 
@@ -24,5 +25,9 @@ class RelevantParameterVariable extends LocalVariable {
 
 from RelevantParameterVariable v
 where
-  not exists(Ssa::WriteDefinition def | def.getWriteAccess().getAstNode() = v.getDefiningAccess())
+  not exists(Ssa::WriteDefinition def | def.getWriteAccess().getAstNode() = v.getDefiningAccess()) and
+  not exists(SuperCall s | s.getEnclosingCallable().getAParameter().getAVariable() = v |
+    // a call to 'super' without any arguments will pass on the parameter.
+    not exists(s.getAnArgument())
+  )
 select v, "The parameter '" + v.getName() + "' is never used."

ruby/ql/test/library-tests/controlflow/graph/raise.rb

@@ -180,3 +180,25 @@ def m16(b1, b2)
     return 3
   end
 end
+
+def m17(b1, b2)
+  begin
+    raise ExceptionA if b1
+  rescue ExceptionA
+    if b2
+      b1 = false
+      retry
+    end
+  end
+end
+
+def m18(b2)
+  b1 = true
+  begin
+    raise ExceptionA if b1
+  rescue ExceptionA
+    if b2
+      b1 = false
+    end
+  end
+end