[libpng16] Avoid conditional directives that break statements in pngrutil.c (Romero

    Malaquias)

1 files changed, 9 insertions, 6 deletions

diff --git a/pngwutil.c b/pngwutil.c
index 87d4981f4..0f98d582d 100644
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -675,10 +675,9 @@ png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height,
     int interlace_type)
 {
    png_byte buf[13]; /* Buffer to store the IHDR info */
+   int is_invalid_depth;
 
    png_debug(1, "in png_write_IHDR");
-   
-   int is_invalid_depth;
 
    /* Check that we have valid input data from the application info */
    switch (color_type)
@@ -728,18 +727,22 @@ png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height,
          break;
 
       case PNG_COLOR_TYPE_GRAY_ALPHA:
-         if (bit_depth != 8 && bit_depth != 16)
+         is_invalid_depth = (bit_depth != 8);
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+         is_invalid_depth = (is_invalid_depth && bit_depth != 16);
+#endif
+         if (is_invalid_depth)
             png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
 
          png_ptr->channels = 2;
          break;
 
       case PNG_COLOR_TYPE_RGB_ALPHA:
+         is_invalid_depth = (bit_depth != 8);
 #ifdef PNG_WRITE_16BIT_SUPPORTED
-         if (bit_depth != 8 && bit_depth != 16)
-#else
-         if (bit_depth != 8)
+         is_invalid_depth = (is_invalid_depth && bit_depth != 16);
 #endif
+         if (is_invalid_depth)
             png_error(png_ptr, "Invalid bit depth for RGBA image");
 
          png_ptr->channels = 4;