On Tue, Aug 30, 2022 at 02:47:58PM +0100, Tom Jones wrote:
> Prior to this change ed script output was in the wrong order, i.e. in
> the order diff_result provides and changes where missing added or
> changed lines. ed edits need to be in reverse order to keep the edited
> file in sync 

The onnly blocking problem with this patch I can see is that output
line offsets aren't being filled in correctly.

For example:

 +			rc = fprintf(dest, "%d,%dc\n", left_start, cc->left.end);
 +		}
 +	}

 ... here, 'rc' should be used to update the line offsets array.

 +
 +	/* Now write out the new lines in all the joined chunks. */