dep/libchdr: Add chd_is_matching_parent()

dep/libchdr/include/libchdr/chd.h

@@ -48,6 +48,7 @@ extern "C" {
 
 #include <libchdr/coretypes.h>
 #include <libchdr/chdconfig.h>
+#include <stdbool.h>
 
 /***************************************************************************
 
@@ -402,6 +403,7 @@ CHD_EXPORT const chd_header *chd_get_header(chd_file *chd);
 CHD_EXPORT chd_error chd_read_header_core_file(core_file *file, chd_header *header);
 CHD_EXPORT chd_error chd_read_header_file(FILE *file, chd_header *header);
 CHD_EXPORT chd_error chd_read_header(const char *filename, chd_header *header);
+CHD_EXPORT bool chd_is_matching_parent(const chd_header* header, const chd_header* parent_header);
 
 
 

dep/libchdr/src/libchdr_chd.c

@@ -2056,6 +2056,27 @@ CHD_EXPORT chd_error chd_read_header(const char *filename, chd_header *header)
 	return err;
 }
 
+CHD_EXPORT bool chd_is_matching_parent(const chd_header* header, const chd_header* parent_header)
+{
+  /* check MD5 if it isn't empty */
+  if (memcmp(nullmd5, header->parentmd5, sizeof(header->parentmd5)) != 0 &&
+      memcmp(nullmd5, parent_header->md5, sizeof(parent_header->md5)) != 0 &&
+      memcmp(parent_header->md5, header->parentmd5, sizeof(header->parentmd5)) != 0)
+	{
+		return false;
+	}
+
+  /* check SHA1 if it isn't empty */
+  if (memcmp(nullsha1, header->parentsha1, sizeof(header->parentsha1)) != 0 &&
+      memcmp(nullsha1, parent_header->sha1, sizeof(parent_header->sha1)) != 0 &&
+      memcmp(parent_header->sha1, header->parentsha1, sizeof(header->parentsha1)) != 0)
+	{
+		return false;
+	}
+
+	return true;
+}
+
 /***************************************************************************
     CORE DATA READ/WRITE
 ***************************************************************************/