From 3e96c3390f5ac57e71bca30a2bdb2887ebb992a9 Mon Sep 17 00:00:00 2001
From: Stephen Heumann <heumann1@illinois.edu>
Date: Wed, 24 Dec 2014 14:54:06 -0600
Subject: [PATCH] Check for TERM changes every time we read input. Also, fix
 possible crashes when termcap entries aren't found.

---
 include/libbb.h  |  2 --
 libbb/lineedit.c | 13 ++++++++++---
 shell/hush.c     |  1 -
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/include/libbb.h b/include/libbb.h
index 1df921378..8af70be68 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1405,8 +1405,6 @@ int read_line_input(const char* prompt, char* command, int maxsize) FAST_FUNC;
 	read_line_input(prompt, command, maxsize)
 #endif
 
-void init_termcap(void);
-
 
 #ifndef COMM_LEN
 # ifdef TASK_COMM_LEN
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 51715344d..0a5899537 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -135,6 +135,7 @@ char *right_cmd = ESC"[C";
 char *clear_to_end_of_screen_cmd = ESC"[J";
 #endif
 
+char *old_term = NULL;
 char termcap_string_buf[TERMCAP_BUFSIZ];
 
 /* Terminal escape sequences to process in input (used by read_key) */
@@ -257,7 +258,7 @@ static void add_escape_seq_from_termcap(char *termcap_code, signed char keycode,
 	}
 }
 
-void init_termcap(void)
+static void init_termcap(void)
 {
 	char *term;
 	char *termcap_buffer;
@@ -267,6 +268,11 @@ void init_termcap(void)
 	term = getenv("TERM");
 	if (term == NULL) 
 		term = DEFAULT_TERM;
+	if (old_term && strcmp(term, old_term) == 0) 
+		return;
+	free(old_term);
+	old_term = strdup(term);
+	
 	termcap_buffer = malloc(TERMCAP_BUFSIZ);
 	if (termcap_buffer == NULL)
 		return;
@@ -292,14 +298,14 @@ void init_termcap(void)
 	add_escape_seq_from_termcap("ku", KEYCODE_UP, &string_buf);
 	add_escape_seq_from_termcap("kd", KEYCODE_DOWN, &string_buf);
 	add_escape_seq_from_termcap("kl", KEYCODE_LEFT, &string_buf);
-	if (strcmp(LAST_ESCAPE_SEQ(), ESC"[D") == 0) {
+	if (n_escape_seqs && strcmp(LAST_ESCAPE_SEQ(), ESC"[D") == 0) {
 		add_escape_seq(ESC"[1;3D", KEYCODE_ALT_LEFT);
 		add_escape_seq(ESC"[1;9D", KEYCODE_ALT_LEFT);	// xterm on OS X: command-left 
 		add_escape_seq(ESC"b", KEYCODE_ALT_LEFT);		// OS X Terminal: option-left
 		add_escape_seq(ESC"[1;5D", KEYCODE_CTRL_LEFT);
 	}
 	add_escape_seq_from_termcap("kr", KEYCODE_RIGHT, &string_buf);
-	if (strcmp(LAST_ESCAPE_SEQ(), ESC"[C") == 0) {
+	if (n_escape_seqs && strcmp(LAST_ESCAPE_SEQ(), ESC"[C") == 0) {
 		add_escape_seq(ESC"[1;3C", KEYCODE_ALT_RIGHT);
 		add_escape_seq(ESC"[1;9C", KEYCODE_ALT_RIGHT);	// xterm on OS X: command-right 
 		add_escape_seq(ESC"f", KEYCODE_ALT_RIGHT);		// OS X Terminal: option-right
@@ -2443,6 +2449,7 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
 	}
 
 	init_unicode();
+	init_termcap();
 
 // FIXME: audit & improve this
 	if (maxsize > MAX_LINELEN)
diff --git a/shell/hush.c b/shell/hush.c
index f4f134b54..763187bf2 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -8349,7 +8349,6 @@ int hush_main(int argc, char **argv)
 #endif
 
 #if ENABLE_FEATURE_EDITING
-	init_termcap();
 	G.line_input_state = new_line_input_t(FOR_SHELL);
 #endif