liblzma: Add the internal function lzma_alloc_zero().
diff --git a/src/liblzma/common/common.c b/src/liblzma/common/common.c
index efe6c22..28aa2b7 100644
--- a/src/liblzma/common/common.c
+++ b/src/liblzma/common/common.c
@@ -53,6 +53,27 @@
}
+extern void * lzma_attribute((__malloc__)) lzma_attr_alloc_size(1)
+lzma_alloc_zero(size_t size, const lzma_allocator *allocator)
+{
+ // Some calloc() variants return NULL if called with size == 0.
+ if (size == 0)
+ size = 1;
+
+ void *ptr;
+
+ if (allocator != NULL && allocator->alloc != NULL) {
+ ptr = allocator->alloc(allocator->opaque, 1, size);
+ if (ptr != NULL)
+ memzero(ptr, size);
+ } else {
+ ptr = calloc(1, size);
+ }
+
+ return ptr;
+}
+
+
extern void
lzma_free(void *ptr, const lzma_allocator *allocator)
{
diff --git a/src/liblzma/common/common.h b/src/liblzma/common/common.h
index 42d27d8..b10a72e 100644
--- a/src/liblzma/common/common.h
+++ b/src/liblzma/common/common.h
@@ -234,6 +234,12 @@
extern void *lzma_alloc(size_t size, const lzma_allocator *allocator)
lzma_attribute((__malloc__)) lzma_attr_alloc_size(1);
+/// Allocates memory and zeroes it (like calloc()). This can be faster
+/// than lzma_alloc() + memzero() while being backward compatible with
+/// custom allocators.
+extern void * lzma_attribute((__malloc__)) lzma_attr_alloc_size(1)
+ lzma_alloc_zero(size_t size, const lzma_allocator *allocator);
+
/// Frees memory
extern void lzma_free(void *ptr, const lzma_allocator *allocator);
