1 files changed, 94 insertions, 0 deletions
diff --git a/tests-clay/object/raw/short.c b/tests-clay/object/raw/short.c
new file mode 100644
index 000000000..996f3f7b4
--- /dev/null
+++ b/tests-clay/object/raw/short.c
@@ -0,0 +1,94 @@
+
+#include "clay_libgit2.h"
+
+#include "odb.h"
+#include "hash.h"
+
+void test_object_raw_short__oid_shortener_no_duplicates(void)
+{
+	git_oid_shorten *os;
+	int min_len;
+
+	os = git_oid_shorten_new(0);
+	cl_assert(os != NULL);
+
+	git_oid_shorten_add(os, "22596363b3de40b06f981fb85d82312e8c0ed511");
+	git_oid_shorten_add(os, "ce08fe4884650f067bd5703b6a59a8b3b3c99a09");
+	git_oid_shorten_add(os, "16a0123456789abcdef4b775213c23a8bd74f5e0");
+	min_len = git_oid_shorten_add(os, "ce08fe4884650f067bd5703b6a59a8b3b3c99a09");
+
+	cl_assert(min_len == GIT_OID_HEXSZ + 1);
+
+	git_oid_shorten_free(os);
+}
+
+void test_object_raw_short__oid_shortener_stresstest_git_oid_shorten(void)
+{
+#define MAX_OIDS 1000
+
+	git_oid_shorten *os;
+	char *oids[MAX_OIDS];
+	char number_buffer[16];
+	git_oid oid;
+	size_t i, j;
+
+	int min_len = 0, found_collision;
+
+	os = git_oid_shorten_new(0);
+	cl_assert(os != NULL);
+
+	/*
+	 * Insert in the shortener 1000 unique SHA1 ids
+	 */
+	for (i = 0; i < MAX_OIDS; ++i) {
+		char *oid_text;
+
+		sprintf(number_buffer, "%u", (unsigned int)i);
+		git_hash_buf(&oid, number_buffer, strlen(number_buffer));
+
+		oid_text = git__malloc(GIT_OID_HEXSZ + 1);
+		git_oid_fmt(oid_text, &oid);
+		oid_text[GIT_OID_HEXSZ] = 0;
+
+		min_len = git_oid_shorten_add(os, oid_text);
+		cl_assert(min_len >= 0);
+
+		oids[i] = oid_text;
+	}
+
+	/*
+	 * Compare the first `min_char - 1` characters of each
+	 * SHA1 OID. If the minimizer worked, we should find at
+	 * least one collision
+	 */
+	found_collision = 0;
+	for (i = 0; i < MAX_OIDS; ++i) {
+		for (j = 0; j < MAX_OIDS; ++j) {
+			if (i != j && memcmp(oids[i], oids[j], min_len - 1) == 0)
+				found_collision = 1;
+		}
+	}
+	cl_assert(found_collision == 1);
+
+	/*
+	 * Compare the first `min_char` characters of each
+	 * SHA1 OID. If the minimizer worked, every single preffix
+	 * should be unique.
+	 */
+	found_collision = 0;
+	for (i = 0; i < MAX_OIDS; ++i) {
+		for (j = 0; j < MAX_OIDS; ++j) {
+			if (i != j && memcmp(oids[i], oids[j], min_len) == 0)
+				found_collision = 1;
+		}
+	}
+	cl_assert(found_collision == 0);
+
+	/* cleanup */
+	for (i = 0; i < MAX_OIDS; ++i)
+		git__free(oids[i]);
+
+	git_oid_shorten_free(os);
+
+#undef MAX_OIDS
+}