From 1cab2f8d8c4c456437e5a93c5ee3c202ebb65eda Mon Sep 17 00:00:00 2001
From: Dave Cramer <davecramer@gmail.com>
Date: Fri, 30 Jul 2021 07:27:38 -0400
Subject: [PATCH] fix: backpatch type alias handling in TypeInfoCache PR #1986

---
 .../org/postgresql/jdbc/TypeInfoCache.java    | 50 ++++++++++++-------
 .../test/jdbc2/DatabaseMetaDataCacheTest.java | 11 ++++
 2 files changed, 44 insertions(+), 17 deletions(-)

diff --git a/pgjdbc/src/main/java/org/postgresql/jdbc/TypeInfoCache.java b/pgjdbc/src/main/java/org/postgresql/jdbc/TypeInfoCache.java
index a0504b1052..7f24e3db5e 100644
--- a/pgjdbc/src/main/java/org/postgresql/jdbc/TypeInfoCache.java
+++ b/pgjdbc/src/main/java/org/postgresql/jdbc/TypeInfoCache.java
@@ -28,6 +28,8 @@
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -108,18 +110,29 @@ public class TypeInfoCache implements TypeInfo {
   /**
    * PG maps several alias to real type names. When we do queries against pg_catalog, we must use
    * the real type, not an alias, so use this mapping.
+   * <p>
+   * Additional values used at runtime (including case variants) will be added to the map.
+   * </p>
    */
-  private static final HashMap<String, String> typeAliases;
+  private static final ConcurrentMap<String, String> TYPE_ALIASES = new ConcurrentHashMap<>(20);
 
   static {
-    typeAliases = new HashMap<String, String>();
-    typeAliases.put("smallint", "int2");
-    typeAliases.put("integer", "int4");
-    typeAliases.put("int", "int4");
-    typeAliases.put("bigint", "int8");
-    typeAliases.put("float", "float8");
-    typeAliases.put("boolean", "bool");
-    typeAliases.put("decimal", "numeric");
+    TYPE_ALIASES.put("bool", "bool");
+    TYPE_ALIASES.put("boolean", "bool");
+    TYPE_ALIASES.put("smallint", "int2");
+    TYPE_ALIASES.put("int2", "int2");
+    TYPE_ALIASES.put("int", "int4");
+    TYPE_ALIASES.put("integer", "int4");
+    TYPE_ALIASES.put("int4", "int4");
+    TYPE_ALIASES.put("long", "int8");
+    TYPE_ALIASES.put("int8", "int8");
+    TYPE_ALIASES.put("bigint", "int8");
+    TYPE_ALIASES.put("float", "float4");
+    TYPE_ALIASES.put("float4", "float4");
+    TYPE_ALIASES.put("double", "float8");
+    TYPE_ALIASES.put("float8", "float8");
+    TYPE_ALIASES.put("decimal", "numeric");
+    TYPE_ALIASES.put("numeric", "numeric");
   }
 
   @SuppressWarnings("method.invocation.invalid")
@@ -667,18 +680,21 @@ public synchronized String getJavaClass(int oid) throws SQLException {
     return result == null ? "java.lang.String" : result;
   }
 
-  public String getTypeForAlias(String alias) {
-    String type = typeAliases.get(alias);
+  public String getTypeForAlias(@Nullable String alias) {
+    if (alias == null) {
+      return null;
+    }
+    String type = TYPE_ALIASES.get(alias);
     if (type != null) {
       return type;
     }
-    if (alias.indexOf('"') == -1) {
-      type = typeAliases.get(alias.toLowerCase());
-      if (type != null) {
-        return type;
-      }
+    type = TYPE_ALIASES.get(alias.toLowerCase());
+    if (type == null) {
+      type = alias;
     }
-    return alias;
+    //populate for future use
+    TYPE_ALIASES.put(alias, type);
+    return type;
   }
 
   public int getPrecision(int oid, int typmod) {
diff --git a/pgjdbc/src/test/java/org/postgresql/test/jdbc2/DatabaseMetaDataCacheTest.java b/pgjdbc/src/test/java/org/postgresql/test/jdbc2/DatabaseMetaDataCacheTest.java
index 2382b6e717..d24f067a2b 100644
--- a/pgjdbc/src/test/java/org/postgresql/test/jdbc2/DatabaseMetaDataCacheTest.java
+++ b/pgjdbc/src/test/java/org/postgresql/test/jdbc2/DatabaseMetaDataCacheTest.java
@@ -6,6 +6,7 @@
 package org.postgresql.test.jdbc2;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 
 import org.postgresql.core.TypeInfo;
 import org.postgresql.jdbc.PgConnection;
@@ -81,4 +82,14 @@ public void testGetTypeInfoUsesCache() throws SQLException {
     List<LogRecord> typeQueries = log.getRecordsMatching(SQL_TYPE_QUERY_LOG_FILTER);
     assertEquals("PgDatabaseMetadata.getTypeInfo() resulted in individual queries for SQL typecodes", 0, typeQueries.size());
   }
+
+  @Test
+  public void testTypeForAlias() {
+    TypeInfo ti = con.getTypeInfo();
+    assertEquals("bool", ti.getTypeForAlias("boolean"));
+    assertEquals("bool", ti.getTypeForAlias("Boolean"));
+    assertEquals("bool", ti.getTypeForAlias("Bool"));
+    assertEquals("bogus", ti.getTypeForAlias("bogus"));
+    assertNull(ti.getTypeForAlias(null));
+  }
 }