[Mesa-dev] [PATCH] mesa/main: handle gl_buffer_index correctly

[Francesco Ansanelli]

---
 src/mesa/main/buffers.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/mesa/main/buffers.c b/src/mesa/main/buffers.c
index e8aedde..3ff6061 100644
--- a/src/mesa/main/buffers.c
+++ b/src/mesa/main/buffers.c
@@ -170,7 +170,7 @@ draw_buffer_enum_to_bitmask(const struct gl_context *ctx, GLenum buffer)
  * Helper routine used by glReadBuffer.
  * Given a GLenum naming a color buffer, return the index of the corresponding
  * renderbuffer (a BUFFER_* value).
- * return -1 for an invalid buffer.
+ * return ~0 for an invalid buffer.
  */
 static gl_buffer_index
 read_buffer_enum_to_index(GLenum buffer)
@@ -197,7 +197,7 @@ read_buffer_enum_to_index(GLenum buffer)
       case GL_AUX1:
       case GL_AUX2:
       case GL_AUX3:
-         return BUFFER_COUNT; /* invalid, but not -1 */
+         return BUFFER_COUNT; /* invalid, but not ~0 */
       case GL_COLOR_ATTACHMENT0_EXT:
          return BUFFER_COLOR0;
       case GL_COLOR_ATTACHMENT1_EXT:
@@ -219,7 +219,7 @@ read_buffer_enum_to_index(GLenum buffer)
          if (buffer >= GL_COLOR_ATTACHMENT8 && buffer <= GL_COLOR_ATTACHMENT31)
             return BUFFER_COUNT;
          /* error */
-         return -1;
+         return ~0;
    }
 }
 
@@ -722,11 +722,11 @@ read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb,
    else {
       /* general case / window-system framebuffer */
       if (_mesa_is_gles3(ctx) && !is_legal_es3_readbuffer_enum(buffer))
-         srcBuffer = -1;
+         srcBuffer = ~0;
       else
          srcBuffer = read_buffer_enum_to_index(buffer);
 
-      if (srcBuffer == -1) {
+      if (srcBuffer == ~0u) {
          _mesa_error(ctx, GL_INVALID_ENUM,
                      "%s(invalid buffer %s)", caller,
                      _mesa_enum_to_string(buffer));
-- 
1.7.9.5