From b90825fee42104e67f15477bf1b31e49c50db9dc Mon Sep 17 00:00:00 2001
From: Ilia Maslakov <il.smind@gmail.com>
Date: Wed, 9 Dec 2009 13:28:20 +0300
Subject: [PATCH]     added NULL check before call g_utf8_find_prev_char,
 g_utf8_get_char_validated for more safety.

Signed-off-by: Ilia Maslakov <il.smind@gmail.com>
---
 edit/edit.c | 51 +++++++++++++++++++++++++++++----------------------
 1 file changed, 29 insertions(+), 22 deletions(-)

diff --git a/edit/edit.c b/edit/edit.c
index 7ba73451b..c52fb482c 100644
--- a/edit/edit.c
+++ b/edit/edit.c
@@ -140,7 +140,6 @@ int edit_get_byte (WEdit * edit, long byte_index)
 char *edit_get_byte_ptr (WEdit * edit, long byte_index)
 {
     unsigned long p;
-
     if (byte_index >= (edit->curs1 + edit->curs2) || byte_index < 0)
 	return NULL;
 
@@ -156,13 +155,11 @@ char *edit_get_buf_ptr (WEdit * edit, long byte_index)
 {
     unsigned long p;
 
-    if (byte_index >= (edit->curs1 + edit->curs2) ) {
-        byte_index -= 1;
-    }
+    if (byte_index >= (edit->curs1 + edit->curs2))
+        byte_index--;
 
-    if ( byte_index < 0 ) {
+    if (byte_index < 0)
         return NULL;
-    }
 
     if (byte_index >= edit->curs1) {
 	p = edit->curs1 + edit->curs2 - 1;
@@ -185,18 +182,23 @@ int edit_get_utf (WEdit * edit, long byte_index, int *char_width)
         return '\n';
     }
 
-
     str = edit_get_byte_ptr (edit, byte_index);
+
+    if (str == NULL) {
+        *char_width = 0;
+        return 0;
+    }
+
     res = g_utf8_get_char_validated (str, -1);
 
-    if ( res < 0 ) {
+    if (res < 0) {
         ch = *str;
         width = 0;
     } else {
         ch = res;
         /* Calculate UTF-8 char width */
-        next_ch = g_utf8_next_char(str);
-        if ( next_ch ) {
+        next_ch = g_utf8_next_char (str);
+        if (next_ch) {
             width = next_ch - str;
         } else {
             ch = 0;
@@ -215,36 +217,41 @@ int edit_get_prev_utf (WEdit * edit, long byte_index, int *char_width)
     gchar *next_ch = NULL;
     int width = 0;
 
-    if ( byte_index > 0 ) {
+    if (byte_index > 0)
         byte_index--;
-    }
 
-    ch = edit_get_utf (edit, byte_index, &width);
-    if ( width == 1 ) {
-        *char_width = width;
-        return ch;
-    }
-
-    if ( byte_index >= (edit->curs1 + edit->curs2) || byte_index < 0 ) {
+    if (byte_index >= (edit->curs1 + edit->curs2) || byte_index < 0) {
         *char_width = 0;
         return 0;
     }
 
+    ch = edit_get_utf (edit, byte_index, &width);
+
+    if (width == 1) {
+        *char_width = width;
+        return ch;
+    }
+
     str = edit_get_byte_ptr (edit, byte_index);
     buf = edit_get_buf_ptr (edit, byte_index);
+    if (str == NULL || buf == NULL) {
+        *char_width = 0;
+        return 0;
+    }
     /* get prev utf8 char */
-    if ( str != buf )
+    if (str != buf)
         str = g_utf8_find_prev_char (buf, str);
 
     res = g_utf8_get_char_validated (str, -1);
-    if ( res < 0 ) {
+
+    if (res < 0) {
         ch = *str;
         width = 0;
     } else {
         ch = res;
         /* Calculate UTF-8 char width */
         next_ch = g_utf8_next_char(str);
-        if ( next_ch ) {
+        if (next_ch) {
             width = next_ch - str;
         } else {
             ch = 0;