in safe_mode, exec() will force to use escapeshellcmd(), which will cause problem if pre-added quote.

imagemagick-engine.diff

@@ -472,7 +472,7 @@ function ime_im_cli_check_executable($fullpath) {
        if (!is_executable($fullpath))
                return false;

-       @exec('"' . $fullpath . '" --version', $output);
+       @exec($fullpath . ' --version', $output);

        return count($output) > 0;
 }
@@ -547,7 +547,7 @@ function ime_im_cli_resize( $old_file, $new_file, $width, $height, $crop, $resiz
        $geometry = $width . 'x' . $height;

        // limits are 150mb and 128mb
-       $cmd = "\"$cmd\" \"$old_file\" -limit memory 157286400 -limit map 134217728 -resize $geometr
+       $cmd = "$cmd $old_file -limit memory 157286400 -limit map 134217728 -resize $geometry";
        if ($crop) {
                // '^' is an escape character on Windows
                $cmd .= (ime_is_windows() ? '^^' : '^') . " -gravity center -extent $geometry";
@@ -561,7 +561,7 @@ function ime_im_cli_resize( $old_file, $new_file, $width, $height, $crop, $resiz
        if ( $resize_mode == 'size' )
                $cmd .= ' -strip';

-       $cmd .= ' "' .  $new_file . '"';
+       $cmd .= ' ' .  $new_file ;
        exec($cmd);

        return file_exists($new_file);
@@ -1075,4 +1075,4 @@ function ime_option_page() {
 </div>
 <?php
 }
-?>
\ No newline at end of file
+?>