+#ifdef PNG_READ_SUPPORTED
+#ifdef PNG_BENIGN_ERRORS_SUPPORTED
+void PNGAPI
+png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
+ error_message)
+{
+ if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+ png_chunk_warning(png_ptr, error_message);
+
+ else
+ png_chunk_error(png_ptr, error_message);
+}
+#endif
+#endif /* PNG_READ_SUPPORTED */
+
+void /* PRIVATE */
+png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
+{
+ /* This is always supported, but for just read or just write it
+ * unconditionally does the right thing.
+ */
+# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+ if (png_ptr->mode & PNG_IS_READ_STRUCT)
+# endif
+
+# ifdef PNG_READ_SUPPORTED
+ {
+ if (error < PNG_CHUNK_ERROR)
+ png_chunk_warning(png_ptr, message);
+
+ else
+ png_chunk_benign_error(png_ptr, message);
+ }
+# endif
+
+# if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+ else if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
+# endif
+
+# ifdef PNG_WRITE_SUPPORTED
+ {
+ if (error < PNG_CHUNK_WRITE_ERROR)
+ png_app_warning(png_ptr, message);
+
+ else
+ png_app_error(png_ptr, message);
+ }
+# endif
+}
+
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+PNG_FUNCTION(void,
+png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
+{
+# define fixed_message "fixed point overflow in "
+# define fixed_message_ln ((sizeof fixed_message)-1)
+ int iin;
+ char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
+ memcpy(msg, fixed_message, fixed_message_ln);
+ iin = 0;
+ if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
+ {
+ msg[fixed_message_ln + iin] = name[iin];
+ ++iin;
+ }
+ msg[fixed_message_ln + iin] = 0;
+ png_error(png_ptr, msg);
+}
+#endif
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+/* This API only exists if ANSI-C style error handling is used,
+ * otherwise it is necessary for png_default_error to be overridden.
+ */
+jmp_buf* PNGAPI
+png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
+ size_t jmp_buf_size)
+{
+ /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
+ * and it must not change after that. Libpng doesn't care how big the
+ * buffer is, just that it doesn't change.
+ *
+ * If the buffer size is no *larger* than the size of jmp_buf when libpng is
+ * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
+ * semantics that this call will not fail. If the size is larger, however,
+ * the buffer is allocated and this may fail, causing the function to return
+ * NULL.
+ */
+ if (png_ptr == NULL)
+ return NULL;
+
+ if (png_ptr->jmp_buf_ptr == NULL)
+ {
+ png_ptr->jmp_buf_size = 0; /* not allocated */
+
+ if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
+ png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
+
+ else
+ {
+ png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
+ png_malloc_warn(png_ptr, jmp_buf_size));
+
+ if (png_ptr->jmp_buf_ptr == NULL)
+ return NULL; /* new NULL return on OOM */
+
+ png_ptr->jmp_buf_size = jmp_buf_size;
+ }
+ }
+
+ else /* Already allocated: check the size */
+ {
+ size_t size = png_ptr->jmp_buf_size;
+
+ if (size == 0)
+ {
+ size = (sizeof png_ptr->jmp_buf_local);
+ if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
+ {
+ /* This is an internal error in libpng: somehow we have been left
+ * with a stack allocated jmp_buf when the application regained
+ * control. It's always possible to fix this up, but for the moment
+ * this is a png_error because that makes it easy to detect.
+ */
+ png_error(png_ptr, "Libpng jmp_buf still allocated");
+ /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
+ }
+ }
+
+ if (size != jmp_buf_size)
+ {
+ png_warning(png_ptr, "Application jmp_buf size changed");
+ return NULL; /* caller will probably crash: no choice here */
+ }
+ }
+
+ /* Finally fill in the function, now we have a satisfactory buffer. It is
+ * valid to change the function on every call.
+ */
+ png_ptr->longjmp_fn = longjmp_fn;
+ return png_ptr->jmp_buf_ptr;
+}
+
+void /* PRIVATE */
+png_free_jmpbuf(png_structrp png_ptr)
+{
+ if (png_ptr != NULL)
+ {
+ jmp_buf *jb = png_ptr->jmp_buf_ptr;
+
+ /* A size of 0 is used to indicate a local, stack, allocation of the
+ * pointer; used here and in png.c
+ */
+ if (jb != NULL && png_ptr->jmp_buf_size > 0)
+ {
+
+ /* This stuff is so that a failure to free the error control structure
+ * does not leave libpng in a state with no valid error handling: the
+ * free always succeeds, if there is an error it gets ignored.
+ */
+ if (jb != &png_ptr->jmp_buf_local)
+ {
+ /* Make an internal, libpng, jmp_buf to return here */
+ jmp_buf free_jmp_buf;
+
+ if (!setjmp(free_jmp_buf))
+ {
+ png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
+ png_ptr->jmp_buf_size = 0; /* stack allocation */
+ png_ptr->longjmp_fn = longjmp;
+ png_free(png_ptr, jb); /* Return to setjmp on error */
+ }
+ }
+ }
+
+ /* *Always* cancel everything out: */
+ png_ptr->jmp_buf_size = 0;
+ png_ptr->jmp_buf_ptr = NULL;
+ png_ptr->longjmp_fn = 0;
+ }
+}
+#endif