All: Prevent memory leaks on realloc failures

* p = realloc(p, new_size) does not free the original buffer in case of
  a realloc failure.
* reallocf() can be used to do so, but is not available on all platforms.
* This patch introduces usbi_reallocf() in libusbi.h and use that instead of realloc
* Issue and original patch submitted by Moritz Lipp (trac #27)

1 files changed, 8 insertions, 0 deletions

diff --git a/libusb/libusbi.h b/libusb/libusbi.h
index 9de56a1..41a6bf0 100644
--- a/libusb/libusbi.h
+++ b/libusb/libusbi.h
@@ -110,6 +110,14 @@ static inline void list_del(struct list_head *entry)
 	entry->prev->next = entry->next;
 }
 
+static inline void *usbi_reallocf(void *ptr, size_t size)
+{
+	void *ret = realloc(ptr, size);
+	if (!ret)
+		free(ptr);
+	return ret;
+}
+
 #define container_of(ptr, type, member) ({                      \
         const typeof( ((type *)0)->member ) *mptr = (ptr);    \
         (type *)( (char *)mptr - offsetof(type,member) );})