Bug 5858 - Make the chanvars.c functions return a 'const char *'

This should prevent us from unintentionally changing variable
values when they're returned from pbx_builtin_getvar_helper.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@7304 65c4cc65-6c06-0410-ace0-fbb531ad65f3

8 files changed, 31 insertions, 30 deletions

diff --git a/apps/app_chanspy.c b/apps/app_chanspy.c
index 7d9061579..80b271ec0 100644
--- a/apps/app_chanspy.c
+++ b/apps/app_chanspy.c
@@ -468,7 +468,7 @@ static int chanspy_exec(struct ast_channel *chan, void *data)
 		prev=NULL;
 		while(peer) {
 			if (peer != chan) {
-				char *group = NULL;
+				const char *group = NULL;
 				int igrp = 1;
 
 				if (peer == prev && !chosen) {
diff --git a/apps/app_groupcount.c b/apps/app_groupcount.c
index aa848c2d5..0d35ca394 100644
--- a/apps/app_groupcount.c
+++ b/apps/app_groupcount.c
@@ -56,7 +56,6 @@ static int group_count_exec(struct ast_channel *chan, void *data)
 	char group[80] = "";
 	char category[80] = "";
 	char ret[80] = "";
-	char *grp;
 	static int deprecation_warning = 0;
 
 	LOCAL_USER_ADD(u);
@@ -69,7 +68,7 @@ static int group_count_exec(struct ast_channel *chan, void *data)
 	ast_app_group_split_group(data, group, sizeof(group), category, sizeof(category));
 
 	if (ast_strlen_zero(group)) {
-		grp = pbx_builtin_getvar_helper(chan, category);
+		const char *grp = pbx_builtin_getvar_helper(chan, category);
 		strncpy(group, grp, sizeof(group) - 1);
 	}
 
diff --git a/apps/app_macro.c b/apps/app_macro.c
index 72b75777c..f36e979c5 100644
--- a/apps/app_macro.c
+++ b/apps/app_macro.c
@@ -89,6 +89,8 @@ LOCAL_USER_DECL;
 
 static int macro_exec(struct ast_channel *chan, void *data)
 {
+	const char *s;
+
 	char *tmp;
 	char *cur, *rest;
 	char *macro;
@@ -101,8 +103,7 @@ static int macro_exec(struct ast_channel *chan, void *data)
 	int oldpriority;
 	char pc[80], depthc[12];
 	char oldcontext[AST_MAX_CONTEXT] = "";
-	char *offsets;
-	int offset, depth;
+	int offset, depth = 0;
 	int setmacrocontext=0;
 	int autoloopflag;
   
@@ -120,13 +121,9 @@ static int macro_exec(struct ast_channel *chan, void *data)
 	LOCAL_USER_ADD(u);
 
 	/* Count how many levels deep the rabbit hole goes */
-	tmp = pbx_builtin_getvar_helper(chan, "MACRO_DEPTH");
-	if (tmp) {
-		sscanf(tmp, "%d", &depth);
-	} else {
-		depth = 0;
-	}
-
+	s = pbx_builtin_getvar_helper(chan, "MACRO_DEPTH");
+	if (s)
+		sscanf(s, "%d", &depth);
 	if (depth >= 7) {
 		ast_log(LOG_ERROR, "Macro():  possible infinite loop detected.  Returning early.\n");
 		LOCAL_USER_REMOVE(u);
@@ -193,12 +190,13 @@ static int macro_exec(struct ast_channel *chan, void *data)
 	chan->priority = 1;
 
 	while((cur = strsep(&rest, "|")) && (argc < MAX_ARGS)) {
+		const char *s;
   		/* Save copy of old arguments if we're overwriting some, otherwise
 	   	let them pass through to the other macro */
   		snprintf(varname, sizeof(varname), "ARG%d", argc);
-		oldargs[argc] = pbx_builtin_getvar_helper(chan, varname);
-		if (oldargs[argc])
-			oldargs[argc] = strdup(oldargs[argc]);
+		s = pbx_builtin_getvar_helper(chan, varname);
+		if (s)
+			oldargs[argc] = strdup(s);
 		pbx_builtin_setvar_helper(chan, varname, cur);
 		argc++;
 	}
@@ -286,6 +284,7 @@ static int macro_exec(struct ast_channel *chan, void *data)
 		ast_copy_string(chan->context, oldcontext, sizeof(chan->context));
 		if (!(chan->_softhangup & AST_SOFTHANGUP_ASYNCGOTO)) {
 			/* Copy the extension, so long as we're not in softhangup, where we could be given an asyncgoto */
+			const char *offsets;
 			ast_copy_string(chan->exten, oldexten, sizeof(chan->exten));
 			if ((offsets = pbx_builtin_getvar_helper(chan, "MACRO_OFFSET"))) {
 				/* Handle macro offset if it's set by checking the availability of step n + offset + 1, otherwise continue
diff --git a/apps/app_meetme.c b/apps/app_meetme.c
index 3c9bad6f1..fb5f660ea 100644
--- a/apps/app_meetme.c
+++ b/apps/app_meetme.c
@@ -143,8 +143,8 @@ static struct ast_conference {
 	int locked;				/* Is the conference locked? */
 	pthread_t recordthread;			/* thread for recording */
 	pthread_attr_t attr;			/* thread attribute */
-	char *recordingfilename;		/* Filename to record the Conference into */
-	char *recordingformat;			/* Format to record the Conference in */
+	const char *recordingfilename;		/* Filename to record the Conference into */
+	const char *recordingformat;			/* Format to record the Conference in */
 	char pin[AST_MAX_EXTENSION];		/* If protected by a PIN */
 	char pinadmin[AST_MAX_EXTENSION];	/* If protected by a admin PIN */
 	struct ast_conference *next;
@@ -813,8 +813,8 @@ static int conf_run(struct ast_channel *chan, struct ast_conference *conf, int c
 	int duration=20;
 	struct ast_dsp *dsp=NULL;
 	struct ast_app *app;
-	char *agifile;
-	char *agifiledefault = "conf-background.agi";
+	const char *agifile;
+	const char *agifiledefault = "conf-background.agi";
 	char meetmesecs[30] = "";
 	char exitcontext[AST_MAX_CONTEXT] = "";
 	char recordingtmp[AST_MAX_EXTENSION] = "";
@@ -1086,7 +1086,8 @@ static int conf_run(struct ast_channel *chan, struct ast_conference *conf, int c
 		/* Find a pointer to the agi app and execute the script */
 		app = pbx_findapp("agi");
 		if (app) {
-			ret = pbx_exec(chan, app, agifile, 1);
+			char *s = ast_strdupa(agifile);
+			ret = pbx_exec(chan, app, s, 1);
 		} else {
 			ast_log(LOG_WARNING, "Could not find application (agi)\n");
 			ret = -2;
diff --git a/apps/app_queue.c b/apps/app_queue.c
index 7f28a6ece..5564d0fcd 100644
--- a/apps/app_queue.c
+++ b/apps/app_queue.c
@@ -1992,7 +1992,6 @@ static int try_calling(struct queue_ent *qe, const char *options, char *announce
 	char oldcontext[AST_MAX_CONTEXT]="";
 	char queuename[256]="";
 	char *newnum;
-	char *monitorfilename;
 	struct ast_channel *peer;
 	struct ast_channel *which;
 	struct localuser *lpeer;
@@ -2209,7 +2208,7 @@ static int try_calling(struct queue_ent *qe, const char *options, char *announce
 		}
 		/* Begin Monitoring */
 		if (qe->parent->monfmt && *qe->parent->monfmt) {
-			monitorfilename = pbx_builtin_getvar_helper(qe->chan, "MONITOR_FILENAME");
+			const char *monitorfilename = pbx_builtin_getvar_helper(qe->chan, "MONITOR_FILENAME");
 			if (pbx_builtin_getvar_helper(qe->chan, "MONITOR_EXEC") || pbx_builtin_getvar_helper(qe->chan, "MONITOR_EXEC_ARGS"))
 				which = qe->chan;
 			else
@@ -2845,7 +2844,7 @@ static int queue_exec(struct ast_channel *chan, void *data)
 	char *options = NULL;
 	char *url = NULL;
 	char *announceoverride = NULL;
-	char *user_priority;
+	const char *user_priority;
 	int prio;
 	char *queuetimeoutstr = NULL;
 	enum queue_result reason = QUEUE_UNKNOWN;
diff --git a/apps/app_stack.c b/apps/app_stack.c
index d24f2267f..ccf24b2b4 100644
--- a/apps/app_stack.c
+++ b/apps/app_stack.c
@@ -82,7 +82,7 @@ static int pop_exec(struct ast_channel *chan, void *data)
 
 static int return_exec(struct ast_channel *chan, void *data)
 {
-	char *label = pbx_builtin_getvar_helper(chan, STACKVAR);
+	const char *label = pbx_builtin_getvar_helper(chan, STACKVAR);
 
 	if (ast_strlen_zero(label)) {
 		ast_log(LOG_ERROR, "Return without Gosub: stack is empty\n");
diff --git a/apps/app_while.c b/apps/app_while.c
index 7c98afe80..1c91446aa 100644
--- a/apps/app_while.c
+++ b/apps/app_while.c
@@ -122,7 +122,7 @@ static int execif_exec(struct ast_channel *chan, void *data) {
 #define VAR_SIZE 64
 
 
-static char *get_index(struct ast_channel *chan, const char *prefix, int index) {
+static const char *get_index(struct ast_channel *chan, const char *prefix, int index) {
 	char varname[VAR_SIZE];
 
 	snprintf(varname, VAR_SIZE, "%s_%d", prefix, index);
@@ -209,15 +209,15 @@ static int _while_exec(struct ast_channel *chan, void *data, int end)
 {
 	int res=0;
 	struct localuser *u;
-	char *while_pri = NULL;
-	char *goto_str = NULL, *my_name = NULL;
-	char *condition = NULL, *label = NULL;
+	const char *while_pri = NULL;
+	char *my_name = NULL;
+	const char *condition = NULL, *label = NULL;
 	char varname[VAR_SIZE], end_varname[VAR_SIZE];
 	const char *prefix = "WHILE";
 	size_t size=0;
 	int used_index_i = -1, x=0;
 	char used_index[VAR_SIZE] = "0", new_index[VAR_SIZE] = "0";
-	
+
 	if (!chan) {
 		/* huh ? */
 		return -1;
@@ -271,6 +271,7 @@ static int _while_exec(struct ast_channel *chan, void *data, int end)
 
 	if (!end && !ast_true(condition)) {
 		/* Condition Met (clean up helper vars) */
+		const char *goto_str;
 		pbx_builtin_setvar_helper(chan, varname, NULL);
 		pbx_builtin_setvar_helper(chan, my_name, NULL);
         snprintf(end_varname,VAR_SIZE,"END_%s",varname);
@@ -291,6 +292,7 @@ static int _while_exec(struct ast_channel *chan, void *data, int end)
 	}
 
 	if (!end && !while_pri) {
+		char *goto_str;
 		size = strlen(chan->context) + strlen(chan->exten) + 32;
 		goto_str = alloca(size);
 		memset(goto_str, 0, size);
@@ -302,6 +304,7 @@ static int _while_exec(struct ast_channel *chan, void *data, int end)
 		/* END of loop */
 		snprintf(end_varname, VAR_SIZE, "END_%s", varname);
 		if (! pbx_builtin_getvar_helper(chan, end_varname)) {
+			char *goto_str;
 			size = strlen(chan->context) + strlen(chan->exten) + 32;
 			goto_str = alloca(size);
 			memset(goto_str, 0, size);
diff --git a/apps/app_zapscan.c b/apps/app_zapscan.c
index ed0c77977..337f52815 100644
--- a/apps/app_zapscan.c
+++ b/apps/app_zapscan.c
@@ -296,7 +296,6 @@ static int conf_exec(struct ast_channel *chan, void *data)
 	char confstr[80] = "", *tmp = NULL;
 	struct ast_channel *tempchan = NULL, *lastchan = NULL,*ichan = NULL;
 	struct ast_frame *f;
-	char *mygroup;
 	char *desired_group;
 	int input=0,search_group=0;
 	
@@ -335,6 +334,7 @@ static int conf_exec(struct ast_channel *chan, void *data)
 			break;
 		
 		if (tempchan && search_group) {
+			const char *mygroup;
 			if((mygroup = pbx_builtin_getvar_helper(tempchan, "GROUP")) && (!strcmp(mygroup, desired_group))) {
 				ast_verbose(VERBOSE_PREFIX_3 "Found Matching Channel %s in group %s\n", tempchan->name, desired_group);
 			} else {