diff --git a/mozilla/js/src/jsregexp.c b/mozilla/js/src/jsregexp.c
index d42d5f149e0..384eea674a1 100644
--- a/mozilla/js/src/jsregexp.c
+++ b/mozilla/js/src/jsregexp.c
@@ -2872,6 +2872,9 @@ ExecuteREBytecode(REGlobalData *gData, REMatchState *x)
                 cap = &x->parens[parenIndex];
                 cap->length = x->cp - (gData->cpbegin + cap->index);
                 op = (REOp) *pc++;
+
+                if (!result)
+                    result = x;
                 continue;
 
               case REOP_ASSERT: