Ticket #1858: Segmentation fault when search in different encodings

Test case:
1. Make two files with same content but with different encodings (for example, in UTF-8 and KOI8-R);
2. Open UTF-8 file for editing. Press Alt+e and set 'UTF-8' encoding;
3. Search someting
4. exit from editor and open file with 'KOI8-R' encoding;
5. You must see a dots. Now press shift+F7 (continue search);
6. Segfault here

Fix issue:
Now function mc_search__recode_str() returns newly allocated string in any case

Signed-off-by: Slava Zanko <slavazanko@gmail.com>

src/search/lib.c

@@ -67,11 +67,19 @@ mc_search__recode_str (const char *str, gsize str_len,
     }
 
     conv = g_iconv_open (charset_to, charset_from);
-    if (conv == INVALID_CONV)
-        return NULL;
+    if (conv == INVALID_CONV) {
+        *bytes_written = str_len;
+        return g_strndup (str, str_len);
+    }
 
     ret = g_convert_with_iconv (str, str_len, conv, &bytes_read, bytes_written, NULL);
     g_iconv_close (conv);
+
+    if (ret == NULL) {
+        *bytes_written = str_len;
+        return g_strndup (str, str_len);
+    }
+
     return ret;
 }
 
@@ -152,8 +160,6 @@ mc_search__tolower_case_str (const char *charset, const char *str, gsize str_len
 
     tmp_str2 = converted_str =
         mc_search__recode_str (str, str_len, charset, cp_display, &converted_str_len);
-    if (converted_str == NULL)
-        return NULL;
 
     tmp_len = converted_str_len + 1;
 
@@ -166,8 +172,6 @@ mc_search__tolower_case_str (const char *charset, const char *str, gsize str_len
     tmp_str2 =
         mc_search__recode_str (converted_str, converted_str_len, cp_display, charset, &tmp_len);
     g_free (converted_str);
-    if (tmp_str2 == NULL)
-        return NULL;
 
     ret = g_string_new_len (tmp_str2, tmp_len);
     g_free (tmp_str2);
@@ -206,8 +210,6 @@ mc_search__toupper_case_str (const char *charset, const char *str, gsize str_len
 
     tmp_str2 = converted_str =
         mc_search__recode_str (str, str_len, charset, cp_display, &converted_str_len);
-    if (converted_str == NULL)
-        return NULL;
 
     tmp_len = converted_str_len + 1;
 
@@ -221,8 +223,6 @@ mc_search__toupper_case_str (const char *charset, const char *str, gsize str_len
     tmp_str2 =
         mc_search__recode_str (converted_str, converted_str_len, cp_display, charset, &tmp_len);
     g_free (converted_str);
-    if (tmp_str2 == NULL)
-        return NULL;
 
     ret = g_string_new_len (tmp_str2, tmp_len);
     g_free (tmp_str2);

src/search/search.c

@@ -197,8 +197,6 @@ mc_search_prepare (mc_search_t * lc_mc_search)
             buffer =
                 mc_search__recode_str (lc_mc_search->original, lc_mc_search->original_len, cp_source,
                                        codepages[loop1].id, &recoded_str_len);
-            if (buffer == NULL)
-                continue;
 
             g_ptr_array_add (ret,
                              mc_search__cond_struct_new (lc_mc_search, buffer,