From 5d4121a6311065723426b977a8f080518cdf8738 Mon Sep 17 00:00:00 2001 From: Ned Deily Date: Sat, 12 Oct 2013 15:47:58 -0700 Subject: 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. --- Misc/NEWS | 4 ++++ Modules/readline.c | 40 +++++++++++++++++++++++++--------------- 2 files changed, 29 insertions(+), 15 deletions(-) diff --git a/Misc/NEWS b/Misc/NEWS index c1c9eaa..536ea0e 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -76,6 +76,10 @@ Core and Builtins 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. + Original patch by Ronald Oussoren. + - Issue #18919: If the close() method of a writer in the sunau or wave module failed, second invocation of close() and destructor no more raise an exception. 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; -- cgit v0.12