Don't elide blank lines when accumulating psql command history.

This can change the meaning of queries, if the blank line happens to
occur in the middle of a quoted literal, as per complaint from Tomas Vondra.

Back-patch to all supported branches.

diff --git a/src/bin/psql/input.c b/src/bin/psql/input.c
index 6628c0c30cb6974534eca3d63c241543e946f201..ec0e6e1d49bc253193b934046cc6d6dc9ff1b2fe 100644 (file)
--- a/src/bin/psql/input.c
+++ b/src/bin/psql/input.c
@@ -95,10 +95,10 @@ void
 pg_append_history(const char *s, PQExpBuffer history_buf)
 {
 #ifdef USE_READLINE
-       if (useHistory && s && s[0])
+       if (useHistory && s)
        {
                appendPQExpBufferStr(history_buf, s);
-               if (s[strlen(s) - 1] != '\n')
+               if (!s[0] || s[strlen(s) - 1] != '\n')
                        appendPQExpBufferChar(history_buf, '\n');
        }
 #endif