Avoid unnecessary elimination of duplicated bigrams.

When the number of bigrams is only one, obviously there is
no duplicated bigrams and its elimination is not needed.

This commit comes from the change of PostgreSQL:
c3ccc9ee584b9b015dd9c1931e261e21f3961e5f

The issue which this commit has addressed is basically
harmless, but there is no strong reason not to back-patch
this. So back-patch to all supported versions.

Beena Emerson

diff --git a/bigm_op.c b/bigm_op.c
index bb23c8d..84515b5 100644 (file)
--- a/bigm_op.c
+++ b/bigm_op.c
@@ -284,7 +284,10 @@ generate_bigm(char *str, int slen)
        if ((len = bptr - GETARR(bgm)) == 0)
                return bgm;
 
        if ((len = bptr - GETARR(bgm)) == 0)
                return bgm;
 

-       if (len > 0)
+       /*
+        * Make bigrams unique.
+        */
+       if (len > 1)

        {
                bool    haveDups = false;
 
        {
                bool    haveDups = false;
 


@@ -504,7 +507,7 @@ generate_wildcard_bigm(const char *str, int slen, bool *removeDups)
        /*
         * Make bigrams unique.
         */
        /*
         * Make bigrams unique.
         */

-       if (len > 0)
+       if (len > 1)

        {
                bool    haveDups = false;
 
        {
                bool    haveDups = false;