Experimental change in srcwin_move_point

2 files changed, 16 insertions, 6 deletions

diff --git a/xdelta3/Makefile.am b/xdelta3/Makefile.am
index 662ff02..6ab3a42 100644
--- a/xdelta3/Makefile.am
+++ b/xdelta3/Makefile.am
@@ -59,7 +59,7 @@ endif
 #common_CFLAGS += -O2
 
 # For additional debugging, add -DXD3_DEBUG=1, 2, 3, ...
-xdelta3_CFLAGS = $(C_WFLAGS) $(common_CFLAGS) -DXD3_DEBUG=0
+xdelta3_CFLAGS = $(C_WFLAGS) $(common_CFLAGS) -DXD3_DEBUG=1
 xdelta3_LDADD = -lm
 
 xdelta3decode_CFLAGS = \
@@ -75,9 +75,9 @@ xdelta3decode_CFLAGS = \
         -DVCDIFF_TOOLS=0
 
 xdelta3regtest_CXXFLAGS = \
-        $(CXX_WFLAGS) $(common_CFLAGS) -DNOT_MAIN=1 -DXD3_DEBUG=1
+        $(CXX_WFLAGS) $(common_CFLAGS) -DNOT_MAIN=1 -DXD3_DEBUG=2
 xdelta3regtest_CFLAGS = \
-        $(C_WFLAGS) $(common_CFLAGS) -DNOT_MAIN=1 -DXD3_DEBUG=1
+        $(C_WFLAGS) $(common_CFLAGS) -DNOT_MAIN=1 -DXD3_DEBUG=2
 xdelta3regtest_LDADD = -lm
 
 man1_MANS = xdelta3.1
diff --git a/xdelta3/xdelta3.c b/xdelta3/xdelta3.c
index 985aa7f..74889f2 100644
--- a/xdelta3/xdelta3.c
+++ b/xdelta3/xdelta3.c
@@ -4344,6 +4344,7 @@ static int
 xd3_srcwin_move_point (xd3_stream *stream, usize_t *next_move_point)
 {
   xoff_t logical_input_cksum_pos;
+  xoff_t absolute_input_pos;
   xoff_t source_size;
 
   if (stream->src->eof_known)
@@ -4358,11 +4359,20 @@ xd3_srcwin_move_point (xd3_stream *stream, usize_t *next_move_point)
         }
     }
 
+  absolute_input_pos = stream->total_in + stream->input_position;
+
   /* Begin by advancing at twice the input rate, up to half the
    * maximum window size. */
-  logical_input_cksum_pos = xd3_min((stream->total_in + stream->input_position) * 2,
-                                (stream->total_in + stream->input_position) +
-                                  (stream->src->max_winsize / 2));
+#if 1
+  if (absolute_input_pos < stream->src->max_winsize) {
+    logical_input_cksum_pos = stream->src->max_winsize;
+  } else {
+    logical_input_cksum_pos = absolute_input_pos + stream->src->max_winsize / 2;
+  }
+#else
+  logical_input_cksum_pos = xd3_min(absolute_input_pos * 2,
+                                    absolute_input_pos + (stream->src->max_winsize / 2));
+#endif
 
   /* If srcwin_cksum_pos is already greater, wait until the difference
    * is met. */