Hashcodes were being improperly calculated for public API of libraries.

compiler/java/com/google/dart/compiler/ast/DartToSourceVisitor.java

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 package com.google.dart.compiler.ast;
 
 import com.google.common.collect.Lists;
 import com.google.dart.compiler.common.GenerateSourceMap;
 import com.google.dart.compiler.common.HasSourceInfo;
 import com.google.dart.compiler.common.SourceMapping;
 import com.google.dart.compiler.util.TextOutput;
 import com.google.debugging.sourcemap.FilePosition;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 
 /**
  * Used by {@link DartNode} to generate Dart source from an AST subtree.
  */
 public class DartToSourceVisitor extends DartVisitor {
 
   private final TextOutput out;
   private boolean buildMappings;
   private List<SourceMapping> mappings = Lists.newArrayList();
   private final boolean isDiet;
 
+  private final boolean calculateHash;

[jbrosenberg, 2011/10/11 14:58:44]

Much cleaner!

+  
   public DartToSourceVisitor(TextOutput out) {
     this(out, false);
   }
 
   public DartToSourceVisitor(TextOutput out, boolean isDiet) {
     this.out = out;
     this.isDiet = isDiet;
+    this.calculateHash = false;
   }
-
+  
+  public DartToSourceVisitor(TextOutput out, boolean isDiet, boolean calculateHash) {
+    this.out = out;
+    this.isDiet = isDiet;
+    this.calculateHash = calculateHash;
+  }
+  
   public void generateSourceMap(boolean generate) {
     this.buildMappings = generate;
   }
 
   public void writeSourceMap(Appendable out, String name) throws IOException {
     GenerateSourceMap generator = new GenerateSourceMap();
     for (SourceMapping m : mappings) {
       generator.addMapping(m.getNode(), m.getStart(), m.getEnd());
     }
     generator.appendTo(out, name);
@@ skipping 51 matching lines @@
       p(">");
     }
   }
 
   @Override
   public boolean visit(DartFunctionTypeAlias x, DartContext ctx) {
     p("typedef ");
 
     if (x.getReturnTypeNode() != null) {
       accept(x.getReturnTypeNode());
-    } else {
-      p("function ");
     }
 
     p(" ");
     accept(x.getName());
     pTypeParameters(x.getTypeParameters());
 
     p("(");
     printSeparatedByComma(x.getParameters());
     p(")");
 
     p(";");
     nl();
     nl();
     return false;
   }
 
   @Override
   public boolean visit(DartClass x, DartContext ctx) {
+    int start = 0;
+    if (calculateHash == true) {
+      start = out.getPosition();
+    }
+    
     if (x.isInterface()) {
       p("interface ");
     } else {
       p("class ");
     }
     accept(x.getName());
     pTypeParameters(x.getTypeParameters());
 
     if (x.getSuperclass() != null) {
       p(" extends ");
@@ skipping 28 matching lines @@
     }
 
     p(" {");
     nl();
     indent();
 
     acceptList(x.getMembers());
 
     outdent();
     p("}");
+    if (calculateHash == true) {

[jbrosenberg, 2011/10/11 14:58:44]

Should this appear after the 2 nl(); calls?  Just thinking it makes sense to
have it at the end of everything (since yo u have other calls to nl() prior to
this, etc.)

[codefu, 2011/10/11 18:43:55]

This emulates the work of older code that called trim() before calculating the
hash.  I don't feel that whitespace after the class' "}" adds any value.

[jbrosenberg, 2011/10/11 21:40:13]

But I think we still have calls coming into this method, which don't pass the
'calculateHash' flag, and rely on getting the output returned for a whole node. 
Thus, if this whitespace could affect the hash, it should be included in the
calculation.

[codefu, 2011/10/11 22:07:18]

DartNode.java:
  return out.toString().trim().hashCode();

+      x.setHash(out.toString().substring(start, out.getPosition()).hashCode());
+    }
     nl();
     nl();
     return false;
   }
 
   @Override
   public boolean visit(DartTypeNode x, DartContext ctx) {
     accept(x.getIdentifier());
     List<DartTypeNode> arguments = x.getTypeArguments();
     if (arguments != null && !arguments.isEmpty()) {
@@ skipping 571 matching lines @@
   }
 
   @Override
   public boolean visit(DartFunctionExpression x, DartContext ctx) {
     DartFunction func = x.getFunction();
     if (func.getReturnTypeNode() != null) {
       accept(func.getReturnTypeNode());
       p(" ");
     }
     DartIdentifier name = x.getName();
-    if (name != null) {
-      if (func.getReturnTypeNode() == null) {
-        p("function ");
-      }
-    } else {
-      p("function");
-    }
     pFunctionDeclaration(name, x.getFunction());
     p(" ");
     if (x.getFunction().getBody() != null) {
       pBlock(x.getFunction().getBody(), false);
     }
     return false;
   }
 
   @Override
   public boolean visit(DartIdentifier x, DartContext ctx) {
@@ skipping 199 matching lines @@
   }
 
   private void indent() {
     out.indentIn();
   }
 
   private void outdent() {
     out.indentOut();
   }
 }