journal: add dst_allocated_size parameter for compress_blob

compress_blob took src, src_size, dst and *dst_size, but dst_size
wasn't used as an input parameter with the size of dst, but only as an
output parameter. dst was implicitly assumed to be at least src_size-1.

This code wasn't *wrong*, because the only real caller in
journal-file.c got it right. But it was misleading, and the tests in
test-compress.c got it wrong, and worked only because the output
buffer happened to be the same size as input buffer. So add a seperate
dst_allocated_size parameter to make it explicit what the size of the
buffer is, and to allow test to proceed with different output buffer
sizes.

1 files changed, 4 insertions, 3 deletions

diff --git a/src/journal/test-compress-benchmark.c b/src/journal/test-compress-benchmark.c
index 93ea9c6318..baed0d82a4 100644
--- a/src/journal/test-compress-benchmark.c
+++ b/src/journal/test-compress-benchmark.c
@@ -27,7 +27,8 @@
 #include "string-util.h"
 #include "util.h"
 
-typedef int (compress_t)(const void *src, uint64_t src_size, void *dst, size_t *dst_size);
+typedef int (compress_t)(const void *src, uint64_t src_size, void *dst,
+                         size_t dst_alloc_size, size_t *dst_size);
 typedef int (decompress_t)(const void *src, uint64_t src_size,
                            void **dst, size_t *dst_alloc_size, size_t* dst_size, size_t dst_max);
 
@@ -111,8 +112,8 @@ static void test_compress_decompress(const char* label, const char* type,
 
                 memzero(buf, MIN(size + 1000, MAX_SIZE));
 
-                r = compress(text, size, buf, &j);
-                /* assume compression must be successful except for small inputs */
+                r = compress(text, size, buf, size, &j);
+                /* assume compression must be successful except for small or random inputs */
                 assert_se(r == 0 || (size < 2048 && r == -ENOBUFS) || streq(type, "random"));
 
                 /* check for overwrites */