patch #562492 - prevent duplicate lines in history

also call using_history() to properly initialize history variables

diff --git a/Modules/readline.c b/Modules/readline.c
index 6850b016bda42f87bc2006ab99b602384116110f..1ca8ec3c0922bfe29aa0da7b22ae9bee6080f3c5 100644 (file)
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -552,6 +552,8 @@ flex_complete(char *text, int start, int end)
 static void
 setup_readline(void)
 {
+       using_history();
+
        rl_readline_name = "python";
 #if defined(PYOS_OS2) && defined(PYCC_GCC)
        /* Allow $if term= in .inputrc to work */
@@ -628,8 +630,23 @@ call_readline(char *prompt)
                return p;
        }
        n = strlen(p);
-       if (n > 0)
-               add_history(p);
+       if (n > 0) {
+               char *line;
+               HISTORY_STATE *state = history_get_history_state();
+               if (state->length > 0)
+                       line = history_get(state->length)->line;
+               else
+                       line = "";
+               if (strcmp(p, line))
+                       add_history(p);
+               /* the history docs don't say so, but the address of state
+                  changes each time history_get_history_state is called
+                  which makes me think it's freshly malloc'd memory...
+                  on the other hand, the address of the last line stays the
+                  same as long as history isn't extended, so it appears to
+                  be malloc'd but managed by the history package... */
+               free(state);
+       }
        /* Copy the malloc'ed buffer into a PyMem_Malloc'ed one and
           release the original. */
        q = p;