(docolon): Test (re_buffer.re_nsub > 0) rather than

searching for `\(' to determine whether to return 0 or the empty
string.  Before it would improperly return '' if the pattern
contained a substring like this: `\\('.  From Karl Heuer.
For example, running expr c : '\\(' should print `0'.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/expr.c b/src/expr.c
index 8675438f4..44905b091 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -456,7 +456,7 @@ of the basic regular expression is not portable; it is being ignored"),
   else
     {
       /* Match failed -- return the right kind of null.  */
-      if (strstr (pv->u.s, "\\("))
+      if (re_buffer.re_nsub > 0)
 	v = str_value ("");
       else
 	v = int_value (0);