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, 32 insertions, 1 deletions

diff --git a/include/asterisk/config.h b/include/asterisk/config.h
index 7f0434d88..3b46982b2 100644
--- a/include/asterisk/config.h
+++ b/include/asterisk/config.h
@@ -47,6 +47,14 @@ enum {
 	CONFIG_FLAG_NOREALTIME    = (1 << 3),
 };
 
+/*! Flags for ast_config_text_file_save2()
+ */
+enum config_save_flags {
+	CONFIG_SAVE_FLAG_NONE = (0),
+	/*! Insure a context doesn't effectively change if a template changes (pre 13.2 behavior) */
+	CONFIG_SAVE_FLAG_PRESERVE_EFFECTIVE_CONTEXT = (1 << 0),
+};
+
 #define	CONFIG_STATUS_FILEMISSING	(void *)0
 #define	CONFIG_STATUS_FILEUNCHANGED	(void *)-1
 #define	CONFIG_STATUS_FILEINVALID	(void *)-2
@@ -86,7 +94,8 @@ struct ast_variable {
 
 	int lineno;
 	int object;		/*!< 0 for variable, 1 for object */
-	int blanklines; 	/*!< Number of blanklines following entry */
+	int blanklines;		/*!< Number of blanklines following entry */
+	int inherited;		/*!< 1 for inherited from template or other base */
 	struct ast_comment *precomments;
 	struct ast_comment *sameline;
 	struct ast_comment *trailing; /*!< the last object in the list will get assigned any trailing comments when EOF is hit */
@@ -907,6 +916,28 @@ struct ast_variable *ast_variable_list_append_hint(struct ast_variable **head, s
 int ast_variable_update(struct ast_category *category, const char *variable,
 						const char *value, const char *match, unsigned int object);
 
+/*!
+ * \brief Save a config text file
+ * \since 13.2.0
+ *
+ * \param filename Filename
+ * \param cfg ast_config
+ * \param generator generator
+ * \param flags List of config_save_flags
+ *
+ * \return 0 on success or -1 on failure.
+ */
+int ast_config_text_file_save2(const char *filename, const struct ast_config *cfg, const char *generator, uint32_t flags);
+
+/*!
+ * \brief Save a config text file preserving the pre 13.2 behavior
+ *
+ * \param filename Filename
+ * \param cfg ast_config
+ * \param generator generator
+ *
+ * \return 0 on success or -1 on failure.
+ */
 int ast_config_text_file_save(const char *filename, const struct ast_config *cfg, const char *generator);
 int config_text_file_save(const char *filename, const struct ast_config *cfg, const char *generator) __attribute__((deprecated));