[devel] Fix new bugs in pngvalid.c; it failed to compile.

pngvalid.c

@@ -5286,7 +5286,7 @@ IT(scale_16);
 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED /* the default before 1.5.4 */
 /* png_set_strip_16 */
 static void
-image_transform_png_set_strip_16(PNG_CONST image_transform *this,
+image_transform_png_set_strip_16_set(PNG_CONST image_transform *this,
     transform_display *that, png_structp pp, png_infop pi)
 {
    png_set_strip_16(pp);
@@ -5294,7 +5294,7 @@ image_transform_png_set_strip_16(PNG_CONST image_transform *this,
 }
 
 static void
-image_transform_png_set_strip_16(PNG_CONST image_transform *this,
+image_transform_png_set_strip_16_mod(PNG_CONST image_transform *this,
     image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
 {
    if (that->bit_depth == 16)
@@ -5305,27 +5305,25 @@ image_transform_png_set_strip_16(PNG_CONST image_transform *this,
       if (that->blue_sBIT > 8) that->blue_sBIT = 8;
       if (that->alpha_sBIT > 8) that->alpha_sBIT = 8;
 
-#     ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
-         /* The strip 16 algorithm drops the low 8 bits rather than calculating
-          * 1/257, so we need to adjust the permitted errors appropriately:
-          * Notice that this is only relevant prior to the addition of the
-          * png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!)
-          */
-         {
-            PNG_CONST double d = (255-128.5)/65535;
-            that->rede += d;
-            that->greene += d;
-            that->bluee += d;
-            that->alphae += d;
-         }
-#     endif
+      /* The strip 16 algorithm drops the low 8 bits rather than calculating
+       * 1/257, so we need to adjust the permitted errors appropriately:
+       * Notice that this is only relevant prior to the addition of the
+       * png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!)
+       */
+      {
+         PNG_CONST double d = (255-128.5)/65535;
+         that->rede += d;
+         that->greene += d;
+         that->bluee += d;
+         that->alphae += d;
+      }
    }
 
    this->next->mod(this->next, that, pp, display);
 }
 
 static int
-image_transform_png_set_strip_16(image_transform *this,
+image_transform_png_set_strip_16_add(image_transform *this,
     PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
 {
    UNUSED(colour_type)
@@ -6716,7 +6714,7 @@ gamma_component_validate(PNG_CONST char *name, PNG_CONST validate_info *vi,
              * bit reduction is obtained by simply using the top 8 bits of the
              * value.
              */
-#           ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+#           if 0 /*WAS: #ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED */
                /* This may be required for other components in the future, but
                 * at present the presence of gamma correction effectively
                 * prevents the errors in the component scaling (I don't quite