From e046e1dfab4f62e24f1abbff7757b0d89620f225 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Wed, 16 May 2001 03:29:01 +0000
Subject: [PATCH] The current implementation of BlobInputStream does not
 properly handle 8-bit unsigned data as it blindly casts the byte to an int,
 which java most helpfully promotes to a signed type.  This causes problems
 when you can only return -1 to indicated EOF.

The following patch fixes the bug and has been tested
locally on image data.

Chad David
---
 .../postgresql/largeobject/BlobInputStream.java | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/interfaces/jdbc/org/postgresql/largeobject/BlobInputStream.java b/src/interfaces/jdbc/org/postgresql/largeobject/BlobInputStream.java
index 646ea97005..9a4b67dec6 100644
--- a/src/interfaces/jdbc/org/postgresql/largeobject/BlobInputStream.java
+++ b/src/interfaces/jdbc/org/postgresql/largeobject/BlobInputStream.java
@@ -58,16 +58,24 @@ public class BlobInputStream extends InputStream {
    */
   public int read() throws java.io.IOException {
     try {
-      if(buffer==null || bpos>=buffer.length) {
+      if (buffer == null || bpos >= buffer.length) {
         buffer=lo.read(bsize);
         bpos=0;
       }
 
       // Handle EOF
-      if(bpos>=buffer.length)
+      if(bpos >= buffer.length) {
         return -1;
+      }
 
-      return (int) buffer[bpos++];
+      int ret = (buffer[bpos] & 0x7F);
+      if ((buffer[bpos] &0x80) == 0x80) {
+        ret |= 0x80;
+      }
+
+      bpos++;
+
+      return ret;
     } catch(SQLException se) {
       throw new IOException(se.toString());
     }
@@ -152,5 +160,4 @@ public class BlobInputStream extends InputStream {
     public boolean markSupported() {
 	return true;
     }
-
-}
\ No newline at end of file
+}