--- file.c	2004-01-23 09:41:32.000000000 +0000
+++ new_file.c	2004-10-30 14:34:24.000000000 +0100
@@ -577,10 +577,14 @@
 {
   assert(!data || length > 0);
 
-  if (data &&
-      ((file->ntags == 1 && !(file->flags & ID3_FILE_FLAG_ID3V1)) ||
-       (file->ntags == 2 &&  (file->flags & ID3_FILE_FLAG_ID3V1))) &&
-      file->tags[0].length == length) {
+  if (!data
+      ||  (!(file->ntags == 1 && !(file->flags & ID3_FILE_FLAG_ID3V1)) && 
+           !(file->ntags == 2 &&  (file->flags & ID3_FILE_FLAG_ID3V1)))) {
+    /* no v2 tag. nothing to do */
+    goto done;
+  }
+
+  if (file->tags[0].length == length) {
     /* easy special case: rewrite existing tag in-place */
 
     if (fseek(file->iofile, file->tags[0].location, SEEK_SET) == -1 ||
@@ -589,11 +593,46 @@
       return -1;
 
     goto done;
+  } else {
+    /* the new tag has a different size */
+    int file_size;
+    int remainder_size;
+    char *remainder;
+
+    /* read in the remainder of the file */
+    fseek(file->iofile, 0, SEEK_END);
+    file_size = ftell(file->iofile);
+    remainder_size = file_size - file->tags[0].location - file->tags[0].length;
+    remainder = (char*)malloc(remainder_size);
+    if (fseek(file->iofile, file->tags[0].location + file->tags[0].length, SEEK_SET) == -1 ||
+	fread(remainder, remainder_size, 1, file->iofile) != 1) {
+      free(remainder);
+      return -1;
+    }
+
+    /* write the tag where the old one was */
+    if (fseek(file->iofile, file->tags[0].location, SEEK_SET) == -1 ||
+	fwrite(data, length, 1, file->iofile) != 1) {
+      free(remainder);
+      return -1;
+    }
+
+    /* write the reaminder */
+    if (fwrite(remainder, remainder_size, 1, file->iofile) != 1) {
+      free(remainder);
+      return -1;
   }
 
-  /* hard general case: rewrite entire file */
+    free(remainder);
 
-  /* ... */
+    /* flush the FILE */
+    if (fflush(file->iofile) == EOF)
+      return -1;
+
+    /* truncate if required */
+    if (ftell(file->iofile) < file_size)
+      ftruncate(fileno(file->iofile), ftell(file->iofile));
+  }
 
  done:
   return 0;