title: Json_decode returning truncated array
body: <p>I'm json_encoding a multi-dimensional array, that dumps something like this:</p>
  
  <pre><code>$array = 
  
  Array
  (
      [a] = Array
          (
              [0] = Array
                  (
                      [x0] = some-string
                      [y0] = some-string
                  )
              [1] = Array
                  (
                      [x1] = some-string
                      [y1] = some-string
                  )
          )
      [b] = Array
          (
              [b1] = Array
                  (
                      [0] = Array
                          (
                              ...
                          )
                  )
              [b2] = Array
                  (
                      [0] = Array
                          (
                              ...
                          )
                  )
              ...
       )
  )
  </code></pre>
  
  <p>But if I do the following and dump the results:</p>
  
  <pre><code>$json = json_encode( $array );
  json_decode( $json, true );
  </code></pre>
  
  <p>Only array "a" is returned:</p>
  
  <pre><code>Array
  (
      [a] = Array
          (
              [0] = Array
                  (
                      [x0] = some-string
                      [y0] = some-string
                  )
              [1] = Array
                  (
                      [x1] = some-string
                      [y1] = some-string
                  )
              ...
          )
      )
  )
  </code></pre>
  
  <p>My first thought was an invalid character causing a parse error, but json_decode should only ever return null from a parse error, not a partially parsed array.</p>
  
  <p>Additional info: The original array is nested up to 9 levels deep in places, and is a ~52,000 character string when encoded.</p>
  
  <p>Update: I'm seeing this problem on PHP 5.2.11, so json_last_error() isn't available.  We have this code running on many different servers and this is the only case of this problem, so I'm guessing it is a server-based problem as opposed to code-based, for whatever that is worth.</p>
  
  <p>Any ideas?</p>