[Python-checkins] cpython: Issue #18458: Prevent crashes with newer versions of libedit. Its readline
ned.deily
python-checkins at python.org
Sat Sep 7 00:17:07 CEST 2013
http://hg.python.org/cpython/rev/b6b8a2171aa3
changeset: 85581:b6b8a2171aa3
user: Ned Deily <nad at acm.org>
date: Fri Sep 06 15:16:19 2013 -0700
summary:
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.
files:
Misc/NEWS | 3 +++
Modules/readline.c | 34 ++++++++++++++++++++++------------
2 files changed, 25 insertions(+), 12 deletions(-)
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -56,6 +56,9 @@
Library
-------
+- Issue #18458: Prevent crashes with newer versions of libedit. Its readline
+ emulation has changed from 0-based indexing to 1-based like gnu readline.
+
- Issue #18852: Handle case of ``readline.__doc__`` being ``None`` in the new
readline activation code in ``site.py``.
diff --git a/Modules/readline.c b/Modules/readline.c
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -63,6 +63,8 @@
*/
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
@@ -627,21 +629,21 @@
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;
}
}
@@ -974,6 +976,17 @@
*/
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();
@@ -1178,11 +1191,8 @@
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;
--
Repository URL: http://hg.python.org/cpython
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