Upload photo link is ignoring selected text for Markdown and plain text/HTML users.

catch_uploaded_photo_fix.js

// TL;DR: Upload photo link is ignoring selected text for 
// Markdown and plain text/HTML users.

// Go to any Tumblr account
// Create text post http://www.tumblr.com/new/text

// Write and select some text. Click on "Upload photo". See the result.
// After uploader iframe has been reloaded, it's calling the function 
// "catch_uploaded_photo" with a param containing the fres link to the
// uploaded pic:

function catch_uploaded_photo(src) {
  //
  if (tinyMCE && (ed = tinyMCE.get('post_two'))) {
    ed.execCommand('mceInsertContent', false, '<img src="' + src + '" />');   
  } else {
    // For people -like me- using Markdown 
    insertTag('post_two', '![](' + src + ')');
    // For people using plain text/HTML
    insertTag('post_two', '<img src="' + src + '" />');
  }
}


// The signature for function insertTag() is the following:
function insertTag(field_id, start, end) {}

// The function is designed to wrap the selection with the inserted tag
// Unfortunately catch_uploaded_photo is skipping the 2nd param
// Side effect is that the link with the new photo is appended before 
// selection -literally appended, no space- so I get something like:
//
//             ![](link)The originally selected text
//
// Wouldn't it be nicer -and more logical- to respect the user selection
// and made something like:

// For people -like me- using Markdown 
insertTag('post_two', '![', '](' + src + ')');
// For people using plain text/HTML
insertTag('post_two', '<img alt="', '" src="' + src + '" />');

// To get a more sensible result like:
//
//             ![The originally selected text](link)
//
//             <img alt="The originally selected text" src="link" />
//
// Can please someone at tumblr.com think/evaluate/fix this?