avoid wrapping shortfall due to surrogate pairs.

lib/widget.js

@@ -2846,6 +2846,17 @@ main:
           } else {
             // Try to find a character to break on.
             if (i !== line.length) {
+              // <XXX>
+              // Compensate for surrogate length
+              // counts on wrapping (experimental):
+              // NOTE: Could optimize this by putting
+              // it in the parent for loop.
+              if (unicode.isSurrogate(line, i)) i--;
+              for (var s = 0, n = 0; n < i; n++) {
+                if (unicode.isSurrogate(line, n)) s++, n++;
+              }
+              i += s;
+              // </XXX>
               j = i;
               // Break _past_ space.
               // Break _past_ double-width chars.