Fix some refcounting in app_queue.c and change the

hashing used by app_queue.c to be case-insensitive.
This is accomplished by adding a new case-insensitive
hashing function.

This was necessary to prevent bad refcount errors
(and potential crashes) which would occur due to the
fact that queues were initially read from the config
file in a case-sensitive manner. Then, when a user
issued a CLI command or manager action, we allowed
for case-insensitive input and used that input to 
directly try to find the queue in the hash table. The result
was either that we could not find a queue that was input or
worse, we would end up hashing to a completely bogus value
based on the input.

This commit resolves the problem presented in
issue #13703. However, that issue was reported against
1.6.0. Since this fix introduces a behavior change, I am
electing to not place this same fix in to the 1.6.0 or 1.6.1
branches, and instead will opt for a change which does not
change behavior.



git-svn-id: http://svn.digium.com/svn/asterisk/trunk@156883 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 19 insertions, 0 deletions

diff --git a/include/asterisk/strings.h b/include/asterisk/strings.h
index 5ad362e56..142fc7c62 100644
--- a/include/asterisk/strings.h
+++ b/include/asterisk/strings.h
@@ -23,6 +23,8 @@
 #ifndef _ASTERISK_STRINGS_H
 #define _ASTERISK_STRINGS_H
 
+#include <ctype.h>
+
 #include "asterisk/inline_api.h"
 #include "asterisk/utils.h"
 #include "asterisk/threadstorage.h"
@@ -738,4 +740,21 @@ static force_inline int ast_str_hash(const char *str)
 	return abs(hash);
 }
 
+/*!
+ * \brief Compute a hash value on a case-insensitive string
+ *
+ * Uses the same hash algorithm as ast_str_hash, but converts
+ * all characters to lowercase prior to computing a hash. This
+ * allows for easy case-insensitive lookups in a hash table.
+ */
+static force_inline int ast_str_case_hash(const char *str)
+{
+	int hash = 5381;
+
+	while (*str) {
+		hash = hash * 33 ^ tolower(*str++);
+	}
+
+	return abs(hash);
+}
 #endif /* _ASTERISK_STRINGS_H */