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authorNed Deily <nad@acm.org>2013-10-12 22:47:58 (GMT)
committerNed Deily <nad@acm.org>2013-10-12 22:47:58 (GMT)
commit5d4121a6311065723426b977a8f080518cdf8738 (patch)
tree4ba55758608e9a26df8c9a84c5b0d2af51b1cdbf /Modules/readline.c
parenta14034872bfe9b5fca07125e7369b8c7030c164b (diff)
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Issue #18458: Prevent crashes with newer versions of libedit. Its readline
emulation has changed from 0-based indexing to 1-based like gnu readline. Original patch by Ronald Oussoren.
Diffstat (limited to 'Modules/readline.c')
-rw-r--r--Modules/readline.c40
1 files changed, 25 insertions, 15 deletions
diff --git a/Modules/readline.c b/Modules/readline.c
index 71c2423..096c6d1 100644
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -54,14 +54,16 @@ extern char **completion_matches(char *, CPFunction *);
* with the "real" readline and cannot be detected at compile-time,
* hence we use a runtime check to detect if we're using libedit
*
- * Currently there is one know API incompatibility:
+ * Currently there is one known API incompatibility:
* - 'get_history' has a 1-based index with GNU readline, and a 0-based
- * index with libedit's emulation.
+ * index with older versions of libedit's emulation.
* - Note that replace_history and remove_history use a 0-based index
- * with both implementation.
+ * with both implementations.
*/
static int using_libedit_emulation = 0;
static const char libedit_version_tag[] = "EditLine wrapper";
+
+static int libedit_history_start = 0;
#endif /* __APPLE__ */
#ifdef HAVE_RL_COMPLETION_DISPLAY_MATCHES_HOOK
@@ -579,21 +581,21 @@ get_history_item(PyObject *self, PyObject *args)
return NULL;
#ifdef __APPLE__
if (using_libedit_emulation) {
- /* Libedit emulation uses 0-based indexes,
- * the real one uses 1-based indexes,
- * adjust the index to ensure that Python
- * code doesn't have to worry about the
- * difference.
+ /* Older versions of libedit's readline emulation
+ * use 0-based indexes, while readline and newer
+ * versions of libedit use 1-based indexes.
*/
int length = _py_get_history_length();
- idx --;
+
+ idx = idx - 1 + libedit_history_start;
/*
* Apple's readline emulation crashes when
* the index is out of range, therefore
* test for that and fail gracefully.
*/
- if (idx < 0 || idx >= length) {
+ if (idx < (0 + libedit_history_start)
+ || idx >= (length + libedit_history_start)) {
Py_RETURN_NONE;
}
}
@@ -908,6 +910,17 @@ setup_readline(void)
*/
if (using_libedit_emulation)
rl_initialize();
+
+ /* Detect if libedit's readline emulation uses 0-based
+ * indexing or 1-based indexing.
+ */
+ add_history("1");
+ if (history_get(1) == NULL) {
+ libedit_history_start = 0;
+ } else {
+ libedit_history_start = 1;
+ }
+ clear_history();
#endif /* __APPLE__ */
using_history();
@@ -1116,11 +1129,8 @@ call_readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
if (length > 0)
#ifdef __APPLE__
if (using_libedit_emulation) {
- /*
- * Libedit's emulation uses 0-based indexes,
- * the real readline uses 1-based indexes.
- */
- line = (const char *)history_get(length - 1)->line;
+ /* handle older 0-based or newer 1-based indexing */
+ line = (const char *)history_get(length + libedit_history_start - 1)->line;
} else
#endif /* __APPLE__ */
line = (const char *)history_get(length)->line;