Use the correct char_width, fix bug when prompt is empty

Author: Hood

css/jquery.terminal-src.css

@@ -186,6 +186,7 @@ body.full-screen-terminal .terminal {
 .terminal .terminal-output > div:not(.raw) div {
     white-space: nowrap;
 }
+
 .cmd .cmd-prompt > span {
     float: left;
 }
@@ -315,6 +316,11 @@ terminal .terminal-output > div {
 .cmd .cmd-prompt {
     position: relative;
     z-index: 200;
+    /* Make sure prompt margin takes up space so that echo with newline : false
+     * works when prompt is empty
+     */
+    border: 0.01px solid transparent;
+    float: left;
 }
 .cmd [role="presentation"]:not(.cmd-cursor-line) {
     overflow: hidden;

js/jquery.terminal-src.js

@@ -9387,7 +9387,7 @@
                         cmd_prompt.css('margin-left', partial_width);
                         cmd_outer.css('top', -last_row_rect.height);
                         // Measure length of partial line in characters
-                        var char_width = command_line.char_width;
+                        var char_width = self.geometry().char.width;
                         var prompt_margin = Math.round(partial_width / char_width);
                         command_line.__set_prompt_margin(prompt_margin);
                     }