diff --git a/apps/app_speech_utils.c b/apps/app_speech_utils.c
index 939a92f58e43b619d462a0e0331fdbc2ccd76086..c90bc8b5020695c7427dbecb7adc37dc822f6f47 100644
--- a/apps/app_speech_utils.c
+++ b/apps/app_speech_utils.c
@@ -202,6 +202,8 @@ static int speech_text(struct ast_channel *chan, const char *cmd, char *data,
 
 	if (result->text != NULL) {
 		ast_copy_string(buf, result->text, len);
+	} else {
+		buf[0] = '\0';
 	}
 
 	return 0;
@@ -230,6 +232,8 @@ static int speech_grammar(struct ast_channel *chan, const char *cmd, char *data,
 
 	if (result->grammar != NULL) {
 		ast_copy_string(buf, result->grammar, len);
+	} else {
+		buf[0] = '\0';
 	}
 
 	return 0;
@@ -330,6 +334,8 @@ static int speech_read(struct ast_channel *chan, const char *cmd, char *data,
 			results++;
 		snprintf(tmp, sizeof(tmp), "%d", results);
 		ast_copy_string(buf, tmp, len);
+	} else {
+		buf[0] = '\0';
 	}
 
 	return 0;
diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index 2714bb95a6178995fa48e8654fae18cd301fd59b..9282aed8944b5907053a7f78ce79f2a1ddb44bf7 100644
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -11899,7 +11899,11 @@ static int function_iaxpeer(struct ast_channel *chan, const char *cmd, char *dat
 		}
 		if((codec = ast_codec_pref_index(&peer->prefs, atoi(codecnum)))) {
 			ast_copy_string(buf, ast_getformatname(codec), len);
+		} else {
+			buf[0] = '\0';
 		}
+	} else {
+		buf[0] = '\0';
 	}
 
 	peer_unref(peer);
diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 4bebce8670083b83297fc7811f114da5c2310cba..df946846243b2ce59452c8b5e437d5829075cdc4 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -14959,7 +14959,11 @@ static int function_sippeer(struct ast_channel *chan, const char *cmd, char *dat
 		codecnum = strsep(&codecnum, "]"); /* trim trailing ']' if any */
 		if((codec = ast_codec_pref_index(&peer->prefs, atoi(codecnum)))) {
 			ast_copy_string(buf, ast_getformatname(codec), len);
+		} else {
+			buf[0] = '\0';
 		}
+	} else {
+		buf[0] = '\0';
 	}
 
 	unref_peer(peer, "unref_peer from function_sippeer, just before return");
diff --git a/funcs/func_callerid.c b/funcs/func_callerid.c
index 9dfe0d8c7c4dcbf8e823e7de36aaf6dcfaef974b..b59f57a44d53e360732a825db9bea257f9897a47 100644
--- a/funcs/func_callerid.c
+++ b/funcs/func_callerid.c
@@ -51,6 +51,7 @@ static int callerpres_write(struct ast_channel *chan, const char *cmd, char *dat
 static int callerid_read(struct ast_channel *chan, const char *cmd, char *data,
 			 char *buf, size_t len)
 {
+	int res = -1;
 	char *opt = data;
 
 	if (!chan)
@@ -64,10 +65,13 @@ static int callerid_read(struct ast_channel *chan, const char *cmd, char *data,
 
 		if (!strncasecmp("all", data, 3)) {
 			snprintf(buf, len, "\"%s\" <%s>", name, num);
+			res = 0;
 		} else if (!strncasecmp("name", data, 4)) {
 			ast_copy_string(buf, name, len);
+			res = 0;
 		} else if (!strncasecmp("num", data, 3)) {
 			ast_copy_string(buf, num, len);
+			res = 0;
 		} else {
 			ast_log(LOG_ERROR, "Unknown callerid data type '%s'.\n", data);
 		}
@@ -78,32 +82,40 @@ static int callerid_read(struct ast_channel *chan, const char *cmd, char *data,
 			snprintf(buf, len, "\"%s\" <%s>",
 				 S_OR(chan->cid.cid_name, ""),
 				 S_OR(chan->cid.cid_num, ""));
+			res = 0;
 		} else if (!strncasecmp("name", data, 4)) {
 			if (chan->cid.cid_name) {
 				ast_copy_string(buf, chan->cid.cid_name, len);
+				res = 0;
 			}
 		} else if (!strncasecmp("num", data, 3)) {
 			if (chan->cid.cid_num) {
 				ast_copy_string(buf, chan->cid.cid_num, len);
+				res = 0;
 			}
 		} else if (!strncasecmp("ani", data, 3)) {
 			if (!strncasecmp(data + 3, "2", 1)) {
 				snprintf(buf, len, "%d", chan->cid.cid_ani2);
 			} else if (chan->cid.cid_ani) {
 				ast_copy_string(buf, chan->cid.cid_ani, len);
+				res = 0;
 			}
 		} else if (!strncasecmp("dnid", data, 4)) {
 			if (chan->cid.cid_dnid) {
 				ast_copy_string(buf, chan->cid.cid_dnid, len);
+				res = 0;
 			}
 		} else if (!strncasecmp("rdnis", data, 5)) {
 			if (chan->cid.cid_rdnis) {
 				ast_copy_string(buf, chan->cid.cid_rdnis, len);
+				res = 0;
 			}
 		} else if (!strncasecmp("pres", data, 4)) {
 			ast_copy_string(buf, ast_named_caller_presentation(chan->cid.cid_pres), len);
+			res = 0;
 		} else if (!strncasecmp("ton", data, 3)) {
 			snprintf(buf, len, "%d", chan->cid.cid_ton);
+			res = 0;
 		} else {
 			ast_log(LOG_ERROR, "Unknown callerid data type '%s'.\n", data);
 		}
@@ -111,7 +123,7 @@ static int callerid_read(struct ast_channel *chan, const char *cmd, char *data,
 		ast_channel_unlock(chan);
 	}
 
-	return 0;
+	return res;
 }
 
 static int callerid_write(struct ast_channel *chan, const char *cmd, char *data,
diff --git a/funcs/func_cdr.c b/funcs/func_cdr.c
index 3ea1a300831661daa8720e8635890976f515028b..9b73d03f18ed70fea30bca41665377e6d7530df8 100644
--- a/funcs/func_cdr.c
+++ b/funcs/func_cdr.c
@@ -84,7 +84,7 @@ static int cdr_read(struct ast_channel *chan, const char *cmd, char *parse,
 		       ast_test_flag(&flags, OPT_RECURSIVE),
 			   ast_test_flag(&flags, OPT_UNPARSED));
 
-	return 0;
+	return ret ? 0 : -1;
 }
 
 static int cdr_write(struct ast_channel *chan, const char *cmd, char *parse,
diff --git a/funcs/func_curl.c b/funcs/func_curl.c
index 107b4e11e665b12a2ec186c64a29bfe6931cba45..e385ed9e179d0934c453f2db6b059b1245227014 100644
--- a/funcs/func_curl.c
+++ b/funcs/func_curl.c
@@ -397,6 +397,7 @@ AST_THREADSTORAGE_CUSTOM(curl_instance, curl_instance_init, curl_instance_cleanu
 static int acf_curl_exec(struct ast_channel *chan, const char *cmd, char *info, char *buf, size_t len)
 {
 	struct ast_str *str = ast_str_create(16);
+	int ret = -1;
 	AST_DECLARE_APP_ARGS(args,
 		AST_APP_ARG(url);
 		AST_APP_ARG(postdata);
@@ -494,13 +495,14 @@ static int acf_curl_exec(struct ast_channel *chan, const char *cmd, char *info,
 		} else {
 			ast_copy_string(buf, str->str, len);
 		}
+		ret = 0;
 	}
 	ast_free(str);
 
 	if (chan)
 		ast_autoservice_stop(chan);
 	
-	return 0;
+	return ret;
 }
 
 struct ast_custom_function acf_curl = {
diff --git a/funcs/func_groupcount.c b/funcs/func_groupcount.c
index f0d7df1b5f791c6b40d05882f5ca5b99cdc2ab3a..b70a42e94ae13a5f9e2ccf835915ee23cca5ecfa 100644
--- a/funcs/func_groupcount.c
+++ b/funcs/func_groupcount.c
@@ -34,6 +34,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 static int group_count_function_read(struct ast_channel *chan, const char *cmd,
 				     char *data, char *buf, size_t len)
 {
+	int ret = -1;
 	int count = -1;
 	char group[80] = "", category[80] = "";
 
@@ -59,12 +60,14 @@ static int group_count_function_read(struct ast_channel *chan, const char *cmd,
 		ast_app_group_list_unlock();
 	}
 
-	if ((count = ast_app_group_get_count(group, category)) == -1)
+	if ((count = ast_app_group_get_count(group, category)) == -1) {
 		ast_log(LOG_NOTICE, "No group could be found for channel '%s'\n", chan->name);
-	else
+	} else {
 		snprintf(buf, len, "%d", count);
+		ret = 0;
+	}
 
-	return 0;
+	return ret;
 }
 
 static struct ast_custom_function group_count_function = {
@@ -91,9 +94,10 @@ static int group_match_count_function_read(struct ast_channel *chan,
 	if (!ast_strlen_zero(group)) {
 		count = ast_app_group_match_get_count(group, category);
 		snprintf(buf, len, "%d", count);
+		return 0;
 	}
 
-	return 0;
+	return -1;
 }
 
 static struct ast_custom_function group_match_count_function = {
@@ -111,6 +115,7 @@ static struct ast_custom_function group_match_count_function = {
 static int group_function_read(struct ast_channel *chan, const char *cmd,
 			       char *data, char *buf, size_t len)
 {
+	int ret = -1;
 	struct ast_group_info *gi = NULL;
 	
 	ast_app_group_list_rdlock();
@@ -124,12 +129,14 @@ static int group_function_read(struct ast_channel *chan, const char *cmd,
 			break;
 	}
 	
-	if (gi)
+	if (gi) {
 		ast_copy_string(buf, gi->group, len);
+		ret = 0;
+	}
 	
 	ast_app_group_list_unlock();
 	
-	return 0;
+	return ret;
 }
 
 static int group_function_write(struct ast_channel *chan, const char *cmd,
diff --git a/funcs/func_math.c b/funcs/func_math.c
index 45036d5ad76dae7e855809252aaf5a40d6e049a2..3517b16ed186be54f5ef3eaaa2b101f5ba609944 100644
--- a/funcs/func_math.c
+++ b/funcs/func_math.c
@@ -82,14 +82,14 @@ static int math(struct ast_channel *chan, const char *cmd, char *parse,
 	);
 
 	if (ast_strlen_zero(parse)) {
-		ast_log(LOG_WARNING, "Syntax: Math(<number1><op><number 2>[,<type_of_result>]) - missing argument!\n");
+		ast_log(LOG_WARNING, "Syntax: MATH(<number1><op><number 2>[,<type_of_result>]) - missing argument!\n");
 		return -1;
 	}
 
 	AST_STANDARD_APP_ARGS(args, parse);
 
 	if (args.argc < 1) {
-		ast_log(LOG_WARNING, "Syntax: Math(<number1><op><number 2>[,<type_of_result>]) - missing argument!\n");
+		ast_log(LOG_WARNING, "Syntax: MATH(<number1><op><number 2>[,<type_of_result>]) - missing argument!\n");
 		return -1;
 	}
 
diff --git a/funcs/func_odbc.c b/funcs/func_odbc.c
index 0925f7c034124346ce683ac2716d987b8b622889..da7e3eccd901715ee54285bf90b5ad9ada97b914 100644
--- a/funcs/func_odbc.c
+++ b/funcs/func_odbc.c
@@ -367,6 +367,7 @@ static int acf_odbc_read(struct ast_channel *chan, const char *cmd, char *s, cha
 		if (res == SQL_NO_DATA) {
 			ast_verb(4, "Found no rows [%s]\n", sql->str);
 			res1 = 0;
+			buf[0] = '\0';
 			ast_copy_string(rowcount, "0", sizeof(rowcount));
 		} else {
 			ast_log(LOG_WARNING, "Error %d in FETCH [%s]\n", res, sql->str);
@@ -517,6 +518,8 @@ end_acf_read:
 		}
 		odbc_store->data = resultset;
 		ast_channel_datastore_add(chan, odbc_store);
+	} else {
+		buf[0] = '\0';
 	}
 	SQLCloseCursor(stmt);
 	SQLFreeHandle(SQL_HANDLE_STMT, stmt);
diff --git a/funcs/func_timeout.c b/funcs/func_timeout.c
index 33db35e3d6aa2231dfff787d5bd150030a1fa823..625070217b99d25edc1e89dba8287f6f5ffb1368 100644
--- a/funcs/func_timeout.c
+++ b/funcs/func_timeout.c
@@ -74,7 +74,7 @@ static int timeout_read(struct ast_channel *chan, const char *cmd, char *data,
 
 	default:
 		ast_log(LOG_ERROR, "Unknown timeout type specified.\n");
-		break;
+		return -1;
 	}
 
 	return 0;
diff --git a/res/res_smdi.c b/res/res_smdi.c
index 88f562b2d7353681d79d1ca50be5d25c6d33b727..d3440f9d2142e526b5910f9f2c7979f1fa7a65a3 100644
--- a/res/res_smdi.c
+++ b/res/res_smdi.c
@@ -1260,7 +1260,7 @@ static int smdi_msg_read(struct ast_channel *chan, const char *cmd, char *data,
 return_error:
 	ast_module_user_remove(u);
 
-	return 0;
+	return res;
 }
 
 static struct ast_custom_function smdi_msg_retrieve_function = {