Fix param count for functions with rest parameters

This also fixes rest parameters not being included in the function initialization logic, which led to the values being incorrect.
ChatTriggers · Nov 19, 2023 · c208a2b · c208a2b
1 parent 351d930
commit c208a2b
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Showing 4 changed files with 13 additions and 4 deletions.
diff --git a/src/main/java/org/mozilla/javascript/NativeFunction.java b/src/main/java/org/mozilla/javascript/NativeFunction.java
@@ -42,14 +42,13 @@ public boolean hasRest() {
 
     @Override
     public int getLength() {
-        int paramCount = getParamCount() - (hasRest() ? 1 : 0);
         if (getLanguageVersion() != Context.VERSION_1_2) {
-            return paramCount;
+            return getParamCount();
         }
         Context cx = Context.getContext();
         NativeCall activation = ScriptRuntime.findFunctionActivation(cx, this);
         if (activation == null) {
-            return paramCount;
+            return getParamCount();
         }
         return activation.effectiveArgs.length;
     }

diff --git a/src/main/java/org/mozilla/javascript/Parser.java b/src/main/java/org/mozilla/javascript/Parser.java
@@ -2628,6 +2628,11 @@ private VariableDeclaration variables(int declType, int pos, boolean isStatement
                     }
                 }
                 defineSymbol(declType, ts.getString(), inForInit);
+
+                if (rest) {
+                    // Decrement paramCount by 1
+                    currentScriptOrFn.setParamCount(currentScriptOrFn.getParamCount() - 1);
+                }
             }
 
             int lineno = ts.lineno;

diff --git a/src/main/java/org/mozilla/javascript/ast/ScriptNode.java b/src/main/java/org/mozilla/javascript/ast/ScriptNode.java
@@ -236,6 +236,10 @@ public int getParamCount() {
         return paramCount;
     }
 
+    public void setParamCount(int paramCount) {
+        this.paramCount = paramCount;
+    }
+
     public int getParamAndVarCount() {
         if (variableNames == null) codeBug();
         return symbols.size();

diff --git a/src/main/java/org/mozilla/javascript/optimizer/Codegen.java b/src/main/java/org/mozilla/javascript/optimizer/Codegen.java
@@ -1903,6 +1903,7 @@ private void generatePrologue() {
             paramCount = fnCurrent.fnode.getParamCount();
             int varCount = fnCurrent.fnode.getParamAndVarCount();
             boolean[] constDeclarations = fnCurrent.fnode.getParamAndVarConst();
+            boolean hasRest = fnCurrent.fnode.hasRest();
 
             List<AstNode> params = fnCurrent.fnode.getParams();
             Map<Integer, Node> defaultParams = fnCurrent.fnode.getDefaultParams();
@@ -1919,7 +1920,7 @@ private void generatePrologue() {
             short firstUndefVar = -1;
             for (int i = 0; i != varCount; ++i) {
                 short reg = -1;
-                if (i < paramCount) {
+                if (i < paramCount + (hasRest ? 1 : 0)) {
                     if (!inDirectCallFunction) {
                         reg = getNewWordLocal();