config: Add option to NOT preserve effective context when changing a template

Let's say you have a template T with variable VAR1 = ON and you have a
context C(T) that doesn't specify VAR1.  If you read C, the effective value
of VAR1 is ON.  Now you change T VAR1 to OFF and call
ast_config_text_file_save.  The current behavior is that the file gets
re-written with T/VAR1=OFF but C/VAR1=ON is added.  Personally, I think this
is a bug. It's preserving the effective state of C even though I didn't
specify C/VAR1 in th first place.  I believe the behavior should be that if
I didn't specify C/VAR1 originally, then the effective value of C/VAR1 should
continue to follow the inherited state.  Now, if I DID explicitly specify
C/VAR1, the it should be preserved even if the template changes.

Even though I think the existing behavior is a bug, it's been that way forever
so I'm not changing it.  Instead, I've created ast_config_text_file_save2()
that takes a bitmask of flags, one of which is to preserve the effective context
(the current behavior).  The original ast_config_text_file_save calls *2 with
the preserve flag.  If you want the new behavior, call *2 directly without a
flag.

I've also updated Manager UpdateConfig with a new parameter
'PreserveEffectiveContext' whose default is 'yes'.  If you want the new behavior
with UpdateConfig, set 'PreserveEffectiveContext: no'.

Tested-by: George Joseph

Review: https://reviewboard.asterisk.org/r/4297/
........

Merged revisions 430295 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@430296 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 29 insertions, 7 deletions

diff --git a/main/config.c b/main/config.c
index fe3ad3f9a..f454544f2 100644
--- a/main/config.c
+++ b/main/config.c
@@ -1250,8 +1250,11 @@ void ast_category_inherit(struct ast_category *new, const struct ast_category *b
 	strcpy(x->name, base->name);
 	x->inst = base;
 	AST_LIST_INSERT_TAIL(&new->template_instances, x, next);
-	for (var = base->root; var; var = var->next)
-		ast_variable_append(new, variable_clone(var));
+	for (var = base->root; var; var = var->next) {
+		struct ast_variable *cloned = variable_clone(var);
+		cloned->inherited = 1;
+		ast_variable_append(new, cloned);
+	}
 }
 
 struct ast_config *ast_config_new(void)
@@ -2358,11 +2361,16 @@ static void insert_leading_blank_lines(FILE *fp, struct inclfile *fi, struct ast
 
 int config_text_file_save(const char *configfile, const struct ast_config *cfg, const char *generator)
 {
-	return ast_config_text_file_save(configfile, cfg, generator);
+	return ast_config_text_file_save2(configfile, cfg, generator, CONFIG_SAVE_FLAG_PRESERVE_EFFECTIVE_CONTEXT);
 }
 
 int ast_config_text_file_save(const char *configfile, const struct ast_config *cfg, const char *generator)
 {
+	return ast_config_text_file_save2(configfile, cfg, generator, CONFIG_SAVE_FLAG_PRESERVE_EFFECTIVE_CONTEXT);
+}
+
+int ast_config_text_file_save2(const char *configfile, const struct ast_config *cfg, const char *generator, uint32_t flags)
+{
 	FILE *f;
 	char fn[PATH_MAX];
 	struct ast_variable *var;
@@ -2522,13 +2530,27 @@ int ast_config_text_file_save(const char *configfile, const struct ast_config *c
 				AST_LIST_TRAVERSE(&cat->template_instances, x, next) {
 					struct ast_variable *v;
 					for (v = x->inst->root; v; v = v->next) {
-						if (!strcasecmp(var->name, v->name) && !strcmp(var->value, v->value)) {
-							found = 1;
-							break;
+
+						if (flags & CONFIG_SAVE_FLAG_PRESERVE_EFFECTIVE_CONTEXT) {
+							if (!strcasecmp(var->name, v->name) && !strcmp(var->value, v->value)) {
+								found = 1;
+								break;
+							}
+						} else {
+							if (var->inherited) {
+								found = 1;
+								break;
+							} else {
+								if (!strcasecmp(var->name, v->name) && !strcmp(var->value, v->value)) {
+									found = 1;
+									break;
+								}
+							}
 						}
 					}
-					if (found)
+					if (found) {
 						break;
+					}
 				}
 				if (found) {
 					var = var->next;