Fix join_path_components() to not add a leading slash when joining to an

initial null string.

Per report from Robert Haas in testing psql \ir.

diff --git a/src/port/path.c b/src/port/path.c
index 13ca4f3f1c1a8d7f69fc1c600cdf3b1f6d9bdc0f..9cb0b016445fa8e17d189994612b01258dbdf529 100644 (file)
--- a/src/port/path.c
+++ b/src/port/path.c
@@ -212,7 +212,8 @@ join_path_components(char *ret_path,
        }
        if (*tail)
                snprintf(ret_path + strlen(ret_path), MAXPGPATH - strlen(ret_path),
-                                "/%s", tail);
+                               /* only add slash if there is something already in head */
+                                "%s%s", head[0] ? "/" : "", tail);
 }