From 0251dcff1fa53ec3e23182be0ad946deede43abf Mon Sep 17 00:00:00 2001
From: Lukas Eder <lukas.eder@gmail.com>
Date: Fri, 23 Dec 2011 14:42:04 +0000
Subject: [PATCH] [#1015] FindBugs: 7 occurrences of "Bad attempt to compute
 absolute value of signed 32-bit hashcode"

---
 jOOQ/src/main/java/org/jooq/impl/AbstractSelect.java    | 2 +-
 jOOQ/src/main/java/org/jooq/impl/AbstractSubSelect.java | 8 ++++----
 jOOQ/src/main/java/org/jooq/impl/MergeImpl.java         | 4 ++--
 jOOQ/src/main/java/org/jooq/impl/Util.java              | 8 ++++++++
 4 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/impl/AbstractSelect.java b/jOOQ/src/main/java/org/jooq/impl/AbstractSelect.java
index a4bd549fbb..994c917281 100644
--- a/jOOQ/src/main/java/org/jooq/impl/AbstractSelect.java
+++ b/jOOQ/src/main/java/org/jooq/impl/AbstractSelect.java
@@ -123,7 +123,7 @@ abstract class AbstractSelect<R extends Record> extends AbstractResultQuery<R> i
     public final Table<R> asTable() {
         // Its usually better to alias nested selects that are used in
         // the FROM clause of a query
-        return new SelectQueryAsTable<R>(this).as("alias_" + Math.abs(hashCode()));
+        return new SelectQueryAsTable<R>(this).as("alias_" + Util.hash(this));
     }
 
     @Override
diff --git a/jOOQ/src/main/java/org/jooq/impl/AbstractSubSelect.java b/jOOQ/src/main/java/org/jooq/impl/AbstractSubSelect.java
index 857da4b0ee..9632e7353b 100644
--- a/jOOQ/src/main/java/org/jooq/impl/AbstractSubSelect.java
+++ b/jOOQ/src/main/java/org/jooq/impl/AbstractSubSelect.java
@@ -305,8 +305,8 @@ implements
         toSQLReference0(local);
         String enclosed = local.render();
 
-        String subqueryName = "limit_" + Math.abs(enclosed.hashCode());
-        String rownumName = "rownum_" + Math.abs(enclosed.hashCode());
+        String subqueryName = "limit_" + Util.hash(enclosed);
+        String rownumName = "rownum_" + Util.hash(enclosed);
 
         context.sql("select * from (select ")
                .sql(subqueryName)
@@ -368,8 +368,8 @@ implements
         toSQLReference0(local);
         String enclosed = local.render();
 
-        String subqueryName = "limit_" + Math.abs(enclosed.hashCode());
-        String rownumName = "rownum_" + Math.abs(enclosed.hashCode());
+        String subqueryName = "limit_" + Util.hash(enclosed);
+        String rownumName = "rownum_" + Util.hash(enclosed);
 
         context.sql("select * from (select ")
                .sql(subqueryName)
diff --git a/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java b/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java
index b3629724e2..7db58d8291 100644
--- a/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/MergeImpl.java
@@ -322,7 +322,7 @@ implements
             case SQLSERVER:
             case SYBASE: {
                 if (using instanceof Select) {
-                    int hash = Math.abs(using.hashCode());
+                    int hash = Util.hash(using);
 
                     context.sql(" as ")
                            .sql("dummy_")
@@ -335,7 +335,7 @@ implements
                         // Some fields are unnamed
                         // [#579] Correct this
                         String name = StringUtils.isBlank(field.getName())
-                            ? "dummy_" + hash + "_" + Math.abs(field.hashCode())
+                            ? "dummy_" + hash + "_" + Util.hash(field)
                             : field.getName();
 
                         context.sql(separator).literal(name);
diff --git a/jOOQ/src/main/java/org/jooq/impl/Util.java b/jOOQ/src/main/java/org/jooq/impl/Util.java
index e4e5144839..0ae502b1fd 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Util.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Util.java
@@ -628,4 +628,12 @@ final class Util {
     static QueryPartInternal internal(QueryPart part) {
         return part.internalAPI(QueryPartInternal.class);
     }
+
+    /**
+     * Return a non-negative hash code for a {@link QueryPart}, taking into
+     * account FindBugs' <code>RV_ABSOLUTE_VALUE_OF_HASHCODE</code> pattern
+     */
+    static int hash(Object object) {
+        return 0x7FFFFFF & object.hashCode();
+    }
 }
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