[PATCH] JavaHL: Fix return value from the java svn_stream_t read function to be compatible with the txdelta_next_window function

[Vladimir Berezniker]

Greetings,

While working on enhancements for JavaHL I ran into a problem
implementing svn_txdelta_apply
call because txdelta_next_window would segfault while trying to calculate
the streams checksum. I traced it down to code in the InputStream.cpp that
returns -1 when end of stream is reached.  -1 does not work with
txdelta_next_window
because it expects 0 to indicate end of stream. Spot checking other svn
functions, that use streams, shows that they check for greater than 0
return value as indication that there is data to be process.  Also as far
as I can tell  apr_size_t maps to size_t, which implies that it is a signed
type making 0 more sensible than -1 as end of steam indicator.

[[[
    JavaHL: Fix return value from the java svn_stream_t read function to be
compatible with the txdelta_next_window function

    [ in subversion/bindings/javahl/native ]

    * InputStream.cpp
      (read): Return 0 instead of -1 as expected by the txdelta_next_window
function
]]]

Thank you,

Vladimir

Index: subversion/bindings/javahl/native/InputStream.cpp
===================================================================
--- subversion/bindings/javahl/native/InputStream.cpp   (revision 1328758)
+++ subversion/bindings/javahl/native/InputStream.cpp   (working copy)
@@ -99,6 +99,14 @@ svn_error_t *InputStream::read(void *baton, char *
   if (JNIUtil::isJavaExceptionThrown())
     return SVN_NO_ERROR;
 
+  /*
+   * Convert -1 from InputStream.read that means EOF, 0 which is subversion 
equivalent
+   */
+  if(jread == -1)
+    {
+      jread = 0;
+    }
+
   // Put the Java byte array into a helper object to retrieve the
   // data bytes.
   JNIByteArray outdata(data, true);
@@ -107,7 +115,7 @@ svn_error_t *InputStream::read(void *baton, char *
 
   // Catch when the Java method tells us it read too much data.
   if (jread > (jint) *len)
-    jread = -1;
+    jread = 0;
 
   // In the case of success copy the data back to the Subversion
   // buffer.