Merge branch 'main' into multi-pack-index-odb-write

.devcontainer/devcontainer.json

+{
+  "postCreateCommand": "bash .devcontainer/setup.sh"
+}

.devcontainer/setup.sh

+#!/bin/sh
+set -e
+
+sudo apt-get update
+sudo apt-get -y --no-install-recommends install cmake
+
+mkdir build
+cd build
+cmake ..
\ No newline at end of file

.vscode/launch.json

+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "(gdb) Launch",
+            "type": "cppdbg",
+            "request": "launch",
+            "program": "${workspaceFolder}/build/libgit2_clar",
+            "args": [],
+            "stopAtEntry": false,
+            "cwd": "${fileDirname}",
+            "environment": [],
+            "externalConsole": false,
+            "MIMode": "gdb",
+            "setupCommands": [
+                {
+                    "description": "Enable pretty-printing for gdb",
+                    "text": "-enable-pretty-printing",
+                    "ignoreFailures": true
+                }
+            ]
+        }
+    ]
+}
\ No newline at end of file

.vscode/tasks.json

+{
+    // See https://go.microsoft.com/fwlink/?LinkId=733558
+    // for the documentation about the tasks.json format
+    "version": "2.0.0",
+    "tasks": [
+      {
+        "label": "Build",
+        "type": "shell",
+        "command": "cd build && cmake --build . --parallel",
+        "group": "build",
+        "presentation": {
+          "reveal": "always",
+          "panel": "new"
+        }
+      },
+      {
+        "label": "Run Tests",
+        "type": "shell",
+        "command": "build/libgit2_clar -v",
+        "group": "test",
+        "presentation": {
+          "reveal": "always",
+          "panel": "new"
+        }
+      }
+    ]
+  }
\ No newline at end of file

cmake/SelectHashes.cmake

@@ -56,6 +56,7 @@ ELSE()
 	MESSAGE(FATAL_ERROR "Asked for unknown SHA1 backend: ${USE_SHA1}")
 ENDIF()
 
+list(APPEND SRC_SHA1 "hash/sha1.h")
 list(SORT SRC_SHA1)
 
 ADD_FEATURE_INFO(SHA ON "using ${USE_SHA1}")

src/array.h

@@ -41,8 +41,8 @@
 
 typedef git_array_t(char) git_array_generic_t;
 
-/* use a generic array for growth so this can return the new item */
-GIT_INLINE(void *) git_array_grow(void *_a, size_t item_size)
+/* use a generic array for growth, return 0 on success */
+GIT_INLINE(int) git_array_grow(void *_a, size_t item_size)
 {
 	volatile git_array_generic_t *a = _a;
 	size_t new_size;
@@ -59,18 +59,18 @@ GIT_INLINE(void *) git_array_grow(void *_a, size_t item_size)
 	if ((new_array = git__reallocarray(a->ptr, new_size, item_size)) == NULL)
 		goto on_oom;
 
-	a->ptr = new_array; a->asize = new_size; a->size++;
-	return a->ptr + (a->size - 1) * item_size;
+	a->ptr = new_array;
+	a->asize = new_size;
+	return 0;
 
 on_oom:
 	git_array_clear(*a);
-	return NULL;
+	return -1;
 }
 
 #define git_array_alloc(a) \
-	(((a).size >= (a).asize) ? \
-	git_array_grow(&(a), sizeof(*(a).ptr)) : \
-	((a).ptr ? &(a).ptr[(a).size++] : (void *)NULL))
+	(((a).size < (a).asize || git_array_grow(&(a), sizeof(*(a).ptr)) == 0) ? \
+	&(a).ptr[(a).size++] : (void *)NULL)
 
 #define git_array_last(a) ((a).size ? &(a).ptr[(a).size - 1] : (void *)NULL)
 

src/attrcache.c

@@ -127,7 +127,7 @@ static int attr_cache_remove(git_attr_cache *cache, git_attr_file *file)
 {
 	int error = 0;
 	git_attr_file_entry *entry;
-	git_attr_file *old = NULL;
+	git_attr_file *oldfile = NULL;
 
 	if (!file)
 		return 0;
@@ -136,13 +136,13 @@ static int attr_cache_remove(git_attr_cache *cache, git_attr_file *file)
 		return error;
 
 	if ((entry = attr_cache_lookup_entry(cache, file->entry->path)) != NULL)
-		old = git_atomic_compare_and_swap(&entry->file[file->source.type], file, NULL);
+		oldfile = git_atomic_compare_and_swap(&entry->file[file->source.type], file, NULL);
 
 	attr_cache_unlock(cache);
 
-	if (old) {
-		GIT_REFCOUNT_OWN(old, NULL);
-		git_attr_file__free(old);
+	if (oldfile == file) {
+		GIT_REFCOUNT_OWN(file, NULL);
+		git_attr_file__free(file);
 	}
 
 	return error;
@@ -401,8 +401,7 @@ int git_attr_cache__init(git_repository *repo)
 	    (ret = git_pool_init(&cache->pool, 1)) < 0)
 		goto cancel;
 
-	cache = git_atomic_compare_and_swap(&repo->attrcache, NULL, cache);
-	if (cache)
+	if (git_atomic_compare_and_swap(&repo->attrcache, NULL, cache) != NULL)
 		goto cancel; /* raced with another thread, free this but no error */
 
 	git_config_free(cfg);

src/clone.c

@@ -162,37 +162,6 @@ done:
 	return error;
 }
 
-static int update_remote_head_byname(
-	git_repository *repo,
-	const char *remote_name,
-	const char *tracking_branch_name,
-	const char *reflog_message)
-{
-	git_buf tracking_head_name = GIT_BUF_INIT;
-	git_reference *remote_head = NULL;
-	int error;
-
-	if ((error = git_buf_printf(&tracking_head_name,
-		"%s%s/%s",
-		GIT_REFS_REMOTES_DIR,
-		remote_name,
-		GIT_HEAD_FILE)) < 0)
-		goto cleanup;
-
-	error = git_reference_symbolic_create(
-		&remote_head,
-		repo,
-		git_buf_cstr(&tracking_head_name),
-		tracking_branch_name,
-		true,
-		reflog_message);
-
-cleanup:
-	git_reference_free(remote_head);
-	git_buf_dispose(&tracking_head_name);
-	return error;
-}
-
 static int update_remote_head(
 	git_repository *repo,
 	git_remote *remote,
@@ -200,7 +169,9 @@ static int update_remote_head(
 	const char *reflog_message)
 {
 	git_refspec *refspec;
-	git_buf tracking_branch_name = GIT_BUF_INIT;
+	git_reference *remote_head = NULL;
+	git_buf remote_head_name = GIT_BUF_INIT;
+	git_buf remote_branch_name = GIT_BUF_INIT;
 	int error;
 
 	/* Determine the remote tracking ref name from the local branch */
@@ -213,19 +184,30 @@ static int update_remote_head(
 	}
 
 	if ((error = git_refspec_transform(
-		&tracking_branch_name,
+		&remote_branch_name,
 		refspec,
 		git_buf_cstr(target))) < 0)
 		goto cleanup;
 
-	error = update_remote_head_byname(
-		repo,
+	if ((error = git_buf_printf(&remote_head_name,
+		"%s%s/%s",
+		GIT_REFS_REMOTES_DIR,
 		git_remote_name(remote),
-		git_buf_cstr(&tracking_branch_name),
+		GIT_HEAD_FILE)) < 0)
+		goto cleanup;
+
+	error = git_reference_symbolic_create(
+		&remote_head,
+		repo,
+		git_buf_cstr(&remote_head_name),
+		git_buf_cstr(&remote_branch_name),
+		true,
 		reflog_message);
 
 cleanup:
-	git_buf_dispose(&tracking_branch_name);
+	git_reference_free(remote_head);
+	git_buf_dispose(&remote_branch_name);
+	git_buf_dispose(&remote_head_name);
 	return error;
 }
 
@@ -277,19 +259,20 @@ cleanup:
 
 static int update_head_to_branch(
 		git_repository *repo,
-		const char *remote_name,
+		git_remote *remote,
 		const char *branch,
 		const char *reflog_message)
 {
 	int retcode;
 	git_buf remote_branch_name = GIT_BUF_INIT;
 	git_reference* remote_ref = NULL;
+	git_buf default_branch = GIT_BUF_INIT;
 
-	GIT_ASSERT_ARG(remote_name);
+	GIT_ASSERT_ARG(remote);
 	GIT_ASSERT_ARG(branch);
 
 	if ((retcode = git_buf_printf(&remote_branch_name, GIT_REFS_REMOTES_DIR "%s/%s",
-		remote_name, branch)) < 0 )
+		git_remote_name(remote), branch)) < 0 )
 		goto cleanup;
 
 	if ((retcode = git_reference_lookup(&remote_ref, repo, git_buf_cstr(&remote_branch_name))) < 0)
@@ -299,11 +282,18 @@ static int update_head_to_branch(
 			reflog_message)) < 0)
 		goto cleanup;
 
-	retcode = update_remote_head_byname(repo, remote_name, remote_branch_name.ptr, reflog_message);
+	if ((retcode = git_remote_default_branch(&default_branch, remote)) < 0)
+		goto cleanup;
+
+	if (!git_remote__matching_refspec(remote, git_buf_cstr(&default_branch)))
+		goto cleanup;
+
+	retcode = update_remote_head(repo, remote, &default_branch, reflog_message);
 
 cleanup:
 	git_reference_free(remote_ref);
 	git_buf_dispose(&remote_branch_name);
+	git_buf_dispose(&default_branch);
 	return retcode;
 }
 
@@ -388,8 +378,7 @@ static int checkout_branch(git_repository *repo, git_remote *remote, const git_c
 	int error;
 
 	if (branch)
-		error = update_head_to_branch(repo, git_remote_name(remote), branch,
-				reflog_message);
+		error = update_head_to_branch(repo, remote, branch, reflog_message);
 	/* Point HEAD to the same ref as the remote's head */
 	else
 		error = update_head_to_remote(repo, remote, reflog_message);

src/diff_driver.c

@@ -141,18 +141,23 @@ static int diff_driver_funcname(const git_config_entry *entry, void *payload)
 static git_diff_driver_registry *git_repository_driver_registry(
 	git_repository *repo)
 {
-	if (!repo->diff_drivers) {
-		git_diff_driver_registry *reg = git_diff_driver_registry_new();
-		reg = git_atomic_compare_and_swap(&repo->diff_drivers, NULL, reg);
+	git_diff_driver_registry *reg = git_atomic_load(repo->diff_drivers), *newreg;
+	if (reg)
+		return reg;
 
-		if (reg != NULL) /* if we race, free losing allocation */
-			git_diff_driver_registry_free(reg);
-	}
-
-	if (!repo->diff_drivers)
+	newreg = git_diff_driver_registry_new();
+	if (!newreg) {
 		git_error_set(GIT_ERROR_REPOSITORY, "unable to create diff driver registry");
-
-	return repo->diff_drivers;
+		return newreg;
+	}
+	reg = git_atomic_compare_and_swap(&repo->diff_drivers, NULL, newreg);
+	if (!reg) {
+		reg = newreg;
+	} else {
+		/* if we race, free losing allocation */
+		git_diff_driver_registry_free(newreg);
+	}
+	return reg;
 }
 
 static int diff_driver_alloc(

src/repository.c

@@ -1093,8 +1093,7 @@ int git_repository_config__weakptr(git_config **out, git_repository *repo)
 		if (!error) {
 			GIT_REFCOUNT_OWN(config, repo);
 
-			config = git_atomic_compare_and_swap(&repo->_config, NULL, config);
-			if (config != NULL) {
+			if (git_atomic_compare_and_swap(&repo->_config, NULL, config) != NULL) {
 				GIT_REFCOUNT_OWN(config, NULL);
 				git_config_free(config);
 			}
@@ -1164,8 +1163,7 @@ int git_repository_odb__weakptr(git_odb **out, git_repository *repo)
 			return error;
 		}
 
-		odb = git_atomic_compare_and_swap(&repo->_odb, NULL, odb);
-		if (odb != NULL) {
+		if (git_atomic_compare_and_swap(&repo->_odb, NULL, odb) != NULL) {
 			GIT_REFCOUNT_OWN(odb, NULL);
 			git_odb_free(odb);
 		}
@@ -1209,8 +1207,7 @@ int git_repository_refdb__weakptr(git_refdb **out, git_repository *repo)
 		if (!error) {
 			GIT_REFCOUNT_OWN(refdb, repo);
 
-			refdb = git_atomic_compare_and_swap(&repo->_refdb, NULL, refdb);
-			if (refdb != NULL) {
+			if (git_atomic_compare_and_swap(&repo->_refdb, NULL, refdb) != NULL) {
 				GIT_REFCOUNT_OWN(refdb, NULL);
 				git_refdb_free(refdb);
 			}
@@ -1257,8 +1254,7 @@ int git_repository_index__weakptr(git_index **out, git_repository *repo)
 		if (!error) {
 			GIT_REFCOUNT_OWN(index, repo);
 
-			index = git_atomic_compare_and_swap(&repo->_index, NULL, index);
-			if (index != NULL) {
+			if (git_atomic_compare_and_swap(&repo->_index, NULL, index) != NULL) {
 				GIT_REFCOUNT_OWN(index, NULL);
 				git_index_free(index);
 			}

src/thread.h

@@ -74,6 +74,9 @@ typedef git_atomic32 git_atomic_ssize;
 #   include "unix/pthread.h"
 #endif
 
+/*
+ * Atomically sets the contents of *a to be val.
+ */
 GIT_INLINE(void) git_atomic32_set(git_atomic32 *a, int val)
 {
 #if defined(GIT_WIN32)
@@ -87,6 +90,10 @@ GIT_INLINE(void) git_atomic32_set(git_atomic32 *a, int val)
 #endif
 }
 
+/*
+ * Atomically increments the contents of *a by 1, and stores the result back into *a.
+ * @return the result of the operation.
+ */
 GIT_INLINE(int) git_atomic32_inc(git_atomic32 *a)
 {
 #if defined(GIT_WIN32)
@@ -100,10 +107,14 @@ GIT_INLINE(int) git_atomic32_inc(git_atomic32 *a)
 #endif
 }
 
+/*
+ * Atomically adds the contents of *a and addend, and stores the result back into *a.
+ * @return the result of the operation.
+ */
 GIT_INLINE(int) git_atomic32_add(git_atomic32 *a, int32_t addend)
 {
 #if defined(GIT_WIN32)
-	return InterlockedExchangeAdd(&a->val, addend);
+	return InterlockedAdd(&a->val, addend);
 #elif defined(GIT_BUILTIN_ATOMIC)
 	return __atomic_add_fetch(&a->val, addend, __ATOMIC_SEQ_CST);
 #elif defined(GIT_BUILTIN_SYNC)
@@ -113,6 +124,10 @@ GIT_INLINE(int) git_atomic32_add(git_atomic32 *a, int32_t addend)
 #endif
 }
 
+/*
+ * Atomically decrements the contents of *a by 1, and stores the result back into *a.
+ * @return the result of the operation.
+ */
 GIT_INLINE(int) git_atomic32_dec(git_atomic32 *a)
 {
 #if defined(GIT_WIN32)
@@ -126,6 +141,10 @@ GIT_INLINE(int) git_atomic32_dec(git_atomic32 *a)
 #endif
 }
 
+/*
+ * Atomically gets the contents of *a.
+ * @return the contents of *a.
+ */
 GIT_INLINE(int) git_atomic32_get(git_atomic32 *a)
 {
 #if defined(GIT_WIN32)
@@ -143,16 +162,13 @@ GIT_INLINE(void *) git_atomic__compare_and_swap(
 	void * volatile *ptr, void *oldval, void *newval)
 {
 #if defined(GIT_WIN32)
-	volatile void *foundval;
-	foundval = InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval);
-	return (foundval == oldval) ? oldval : newval;
+	return InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval);
 #elif defined(GIT_BUILTIN_ATOMIC)
-	bool success = __atomic_compare_exchange(ptr, &oldval, &newval, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
-	return success ? oldval : newval;
+	void *foundval = oldval;
+	__atomic_compare_exchange(ptr, &foundval, &newval, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
+	return foundval;
 #elif defined(GIT_BUILTIN_SYNC)
-	volatile void *foundval;
-	foundval = __sync_val_compare_and_swap(ptr, oldval, newval);
-	return (foundval == oldval) ? oldval : newval;
+	return __sync_val_compare_and_swap(ptr, oldval, newval);
 #else
 #	error "Unsupported architecture for atomic operations"
 #endif
@@ -164,11 +180,11 @@ GIT_INLINE(volatile void *) git_atomic__swap(
 #if defined(GIT_WIN32)
 	return InterlockedExchangePointer(ptr, newval);
 #elif defined(GIT_BUILTIN_ATOMIC)
-	void * volatile foundval;
+	void * volatile foundval = NULL;
 	__atomic_exchange(ptr, &newval, &foundval, __ATOMIC_SEQ_CST);
 	return foundval;
 #elif defined(GIT_BUILTIN_SYNC)
-	return __sync_lock_test_and_set(ptr, newval);
+	return (volatile void *)__sync_lock_test_and_set(ptr, newval);
 #else
 #	error "Unsupported architecture for atomic operations"
 #endif
@@ -178,9 +194,7 @@ GIT_INLINE(volatile void *) git_atomic__load(void * volatile *ptr)
 {
 #if defined(GIT_WIN32)
 	void *newval = NULL, *oldval = NULL;
-	volatile void *foundval = NULL;
-	foundval = InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval);
-	return foundval;
+	return (volatile void *)InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval);
 #elif defined(GIT_BUILTIN_ATOMIC)
 	return (volatile void *)__atomic_load_n(ptr, __ATOMIC_SEQ_CST);
 #elif defined(GIT_BUILTIN_SYNC)
@@ -192,10 +206,14 @@ GIT_INLINE(volatile void *) git_atomic__load(void * volatile *ptr)
 
 #ifdef GIT_ARCH_64
 
+/*
+ * Atomically adds the contents of *a and addend, and stores the result back into *a.
+ * @return the result of the operation.
+ */
 GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend)
 {
 #if defined(GIT_WIN32)
-	return InterlockedExchangeAdd64(&a->val, addend);
+	return InterlockedAdd64(&a->val, addend);
 #elif defined(GIT_BUILTIN_ATOMIC)
 	return __atomic_add_fetch(&a->val, addend, __ATOMIC_SEQ_CST);
 #elif defined(GIT_BUILTIN_SYNC)
@@ -205,6 +223,9 @@ GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend)
 #endif
 }
 
+/*
+ * Atomically sets the contents of *a to be val.
+ */
 GIT_INLINE(void) git_atomic64_set(git_atomic64 *a, int64_t val)
 {
 #if defined(GIT_WIN32)
@@ -218,6 +239,10 @@ GIT_INLINE(void) git_atomic64_set(git_atomic64 *a, int64_t val)
 #endif
 }
 
+/*
+ * Atomically gets the contents of *a.
+ * @return the contents of *a.
+ */
 GIT_INLINE(int64_t) git_atomic64_get(git_atomic64 *a)
 {
 #if defined(GIT_WIN32)
@@ -297,11 +322,10 @@ GIT_INLINE(int) git_atomic32_get(git_atomic32 *a)
 GIT_INLINE(void *) git_atomic__compare_and_swap(
 	void * volatile *ptr, void *oldval, void *newval)
 {
-	if (*ptr == oldval)
+	void *foundval = *ptr;
+	if (foundval == oldval)
 		*ptr = newval;
-	else
-		oldval = newval;
-	return oldval;
+	return foundval;
 }
 
 GIT_INLINE(volatile void *) git_atomic__swap(
@@ -339,17 +363,50 @@ GIT_INLINE(int64_t) git_atomic64_get(git_atomic64 *a)
 
 #endif
 
-/* Atomically replace oldval with newval
- * @return oldval if it was replaced or newval if it was not
+/*
+ * Atomically replace the contents of *ptr (if they are equal to oldval) with
+ * newval. ptr must point to a pointer or a value that is the same size as a
+ * pointer. This is semantically compatible with:
+ *
+ *   #define git_atomic_compare_and_swap(ptr, oldval, newval) \
+ *   ({                                                       \
+ *       void *foundval = *ptr;                               \
+ *       if (foundval == oldval)                              \
+ *           *ptr = newval;                                   \
+ *       foundval;                                            \
+ *   })
+ *
+ * @return the original contents of *ptr.
  */
-#define git_atomic_compare_and_swap(P,O,N) \
-	git_atomic__compare_and_swap((void * volatile *)P, O, N)
+#define git_atomic_compare_and_swap(ptr, oldval, newval) \
+	git_atomic__compare_and_swap((void * volatile *)ptr, oldval, newval)
 
-#define git_atomic_swap(ptr, val) \
-	(void *)git_atomic__swap((void * volatile *)&ptr, val)
+/*
+ * Atomically replace the contents of v with newval. v must be the same size as
+ * a pointer. This is semantically compatible with:
+ *
+ *   #define git_atomic_swap(v, newval) \
+ *   ({                                 \
+ *       volatile void *old = v;        \
+ *       v = newval;                    \
+ *       old;                           \
+ *   })
+ *
+ * @return the original contents of v.
+ */
+#define git_atomic_swap(v, newval) \
+	(void *)git_atomic__swap((void * volatile *)&(v), newval)
 
-#define git_atomic_load(ptr) \
-	(void *)git_atomic__load((void * volatile *)&ptr)
+/*
+ * Atomically reads the contents of v. v must be the same size as a pointer.
+ * This is semantically compatible with:
+ *
+ *   #define git_atomic_load(v) v
+ *
+ * @return the contents of v.
+ */
+#define git_atomic_load(v) \
+	(void *)git_atomic__load((void * volatile *)&(v))
 
 #if defined(GIT_THREADS)
 

tests/clone/nonetwork.c

@@ -172,7 +172,7 @@ void test_clone_nonetwork__can_checkout_given_branch(void)
 
 	cl_git_pass(git_reference_lookup(&remote_head, g_repo, "refs/remotes/origin/HEAD"));
 	cl_assert_equal_i(GIT_REFERENCE_SYMBOLIC, git_reference_type(remote_head));
-	cl_assert_equal_s("refs/remotes/origin/test", git_reference_symbolic_target(remote_head));
+	cl_assert_equal_s("refs/remotes/origin/master", git_reference_symbolic_target(remote_head));
 
 	git_reference_free(remote_head);
 }

tests/config/read.c

@@ -964,7 +964,7 @@ void test_config_read__get_mapped(void)
 								  "  key9 = off\n");
 	cl_git_pass(git_config_open_ondisk(&cfg, "./testconfig"));
 
-	// check parsing bool and string
+	/* check parsing bool and string */
 	cl_git_pass(git_config_get_mapped(&val, cfg, "header.key1", _test_map1, ARRAY_SIZE(_test_map1)));
 	cl_assert_equal_i(val, MAP_TRUE);
 	cl_git_pass(git_config_get_mapped(&val, cfg, "header.key2", _test_map1, ARRAY_SIZE(_test_map1)));
@@ -986,7 +986,7 @@ void test_config_read__get_mapped(void)
 
 	cl_git_fail(git_config_get_mapped(&val, cfg, "header.key7", _test_map1, ARRAY_SIZE(_test_map1)));
 
-	// check parsing int values
+	/* check parsing int values */
 	cl_git_pass(git_config_get_mapped(&val, cfg, "header.key1", _test_map2, ARRAY_SIZE(_test_map2)));
 	cl_git_pass(git_config_get_int32(&known_good, cfg, "header.key1"));
 	cl_assert_equal_i(val, known_good);

tests/pack/midx.c

@@ -107,4 +107,4 @@ void test_pack_midx__odb_create(void)
 	git_buf_dispose(&expected_midx);
 
 	cl_git_pass(git_futils_rmdir_r("./clone.git", NULL, GIT_RMDIR_REMOVE_FILES));
-}
+}
\ No newline at end of file

tests/remote/fetch.c

@@ -72,7 +72,7 @@ void do_time_travelling_fetch(git_oid *commit1id, git_oid *commit2id,
 		.strings = &refspec_strs,
 	};
 
-	// create two commits in repo 1 and a reference to them
+	/* create two commits in repo 1 and a reference to them */
 	{
 		git_oid empty_tree_id;
 		git_tree *empty_tree;
@@ -92,7 +92,7 @@ void do_time_travelling_fetch(git_oid *commit1id, git_oid *commit2id,
 		git_treebuilder_free(tb);
 	}
 
-	// fetch the reference via the remote
+	/* fetch the reference via the remote */
 	{
 		git_remote *remote;
 
@@ -103,7 +103,7 @@ void do_time_travelling_fetch(git_oid *commit1id, git_oid *commit2id,
 		git_remote_free(remote);
 	}
 
-	// assert that repo2 references the second commit
+	/* assert that repo2 references the second commit */
 	{
 		const git_oid *target;
 		git_reference *ref;
@@ -113,7 +113,7 @@ void do_time_travelling_fetch(git_oid *commit1id, git_oid *commit2id,
 		git_reference_free(ref);
 	}
 
-	// set the reference in repo1 to point to the older commit
+	/* set the reference in repo1 to point to the older commit */
 	{
 		git_reference *ref;
 		git_reference *ref2;
@@ -124,7 +124,7 @@ void do_time_travelling_fetch(git_oid *commit1id, git_oid *commit2id,
 		git_reference_free(ref2);
 	}
 
-	// fetch the reference again
+	/* fetch the reference again */
 	{
 		git_remote *remote;
 
@@ -144,7 +144,7 @@ void test_remote_fetch__dont_update_refs_if_not_descendant_and_not_force(void) {
 
 	do_time_travelling_fetch(&commit1id, &commit2id, false);
 
-	// assert that the reference in repo2 has not changed
+	/* assert that the reference in repo2 has not changed */
 	cl_git_pass(git_reference_lookup(&ref, repo2, REPO2_REFNAME));
 	target = git_reference_target(ref);
 	cl_assert_equal_b(git_oid_cmp(target, &commit2id), 0);
@@ -160,7 +160,7 @@ void test_remote_fetch__do_update_refs_if_not_descendant_and_force(void) {
 
 	do_time_travelling_fetch(&commit1id, &commit2id, true);
 
-	// assert that the reference in repo2 has changed
+	/* assert that the reference in repo2 has changed */
 	cl_git_pass(git_reference_lookup(&ref, repo2, REPO2_REFNAME));
 	target = git_reference_target(ref);
 	cl_assert_equal_b(git_oid_cmp(target, &commit1id), 0);

tests/threads/atomic.c

+#include "clar_libgit2.h"
+
+void test_threads_atomic__atomic32_set(void)
+{
+	git_atomic32 v = {0};
+	git_atomic32_set(&v, 1);
+	cl_assert_equal_i(v.val, 1);
+}
+
+void test_threads_atomic__atomic32_get(void)
+{
+	git_atomic32 v = {1};
+	cl_assert_equal_i(git_atomic32_get(&v), 1);
+}
+
+void test_threads_atomic__atomic32_inc(void)
+{
+	git_atomic32 v = {0};
+	cl_assert_equal_i(git_atomic32_inc(&v), 1);
+	cl_assert_equal_i(v.val, 1);
+}
+
+void test_threads_atomic__atomic32_add(void)
+{
+	git_atomic32 v = {0};
+	cl_assert_equal_i(git_atomic32_add(&v, 1), 1);
+	cl_assert_equal_i(v.val, 1);
+}
+
+void test_threads_atomic__atomic32_dec(void)
+{
+	git_atomic32 v = {1};
+	cl_assert_equal_i(git_atomic32_dec(&v), 0);
+	cl_assert_equal_i(v.val, 0);
+}
+
+void test_threads_atomic__atomic64_set(void)
+{
+#ifndef GIT_ARCH_64
+	cl_skip();
+#else
+	git_atomic64 v = {0};
+	git_atomic64_set(&v, 1);
+	cl_assert_equal_i(v.val, 1);
+#endif
+}
+
+void test_threads_atomic__atomic64_get(void)
+{
+#ifndef GIT_ARCH_64
+	cl_skip();
+#else
+	git_atomic64 v = {1};
+	cl_assert_equal_i(git_atomic64_get(&v), 1);
+#endif
+}
+
+void test_threads_atomic__atomic64_add(void)
+{
+#ifndef GIT_ARCH_64
+	cl_skip();
+#else
+	git_atomic64 v = {0};
+	cl_assert_equal_i(git_atomic64_add(&v, 1), 1);
+	cl_assert_equal_i(v.val, 1);
+#endif
+}
+
+void test_threads_atomic__cas_pointer(void)
+{
+	int *value = NULL;
+	int newvalue1 = 1, newvalue2 = 2;
+
+	/* value is updated */
+	cl_assert_equal_p(git_atomic_compare_and_swap(&value, NULL, &newvalue1), NULL);
+	cl_assert_equal_p(value, &newvalue1);
+
+	/* value is not updated */
+	cl_assert_equal_p(git_atomic_compare_and_swap(&value, NULL, &newvalue2), &newvalue1);
+	cl_assert_equal_p(value, &newvalue1);
+}
+
+void test_threads_atomic__cas_intptr(void)
+{
+	intptr_t value = 0;
+	intptr_t oldvalue;
+	intptr_t newvalue;
+
+	/* value is updated */
+	oldvalue = 0;
+	newvalue = 1;
+	cl_assert_equal_i((intptr_t)git_atomic_compare_and_swap(&value, (void *)oldvalue, (void *)newvalue), 0);
+	cl_assert_equal_i(value, 1);
+
+	/* value is not updated */
+	oldvalue = 0;
+	newvalue = 2;
+	cl_assert_equal_i((intptr_t)git_atomic_compare_and_swap(&value, (void *)oldvalue, (void *)newvalue), 1);
+	cl_assert_equal_i(value, 1);
+}
+
+void test_threads_atomic__swap(void)
+{
+	int *value = NULL;
+	int newvalue = 1;
+
+	cl_assert_equal_p(git_atomic_swap(value, &newvalue), NULL);
+	cl_assert_equal_p(value, &newvalue);
+
+	cl_assert_equal_p(git_atomic_swap(value, NULL), &newvalue);
+	cl_assert_equal_p(value, NULL);
+}
+
+void test_threads_atomic__load_ptr(void)
+{
+	int value = 1;
+	int *ptr = &value;
+	cl_assert_equal_p(git_atomic_load(ptr), &value);
+}
+
+void test_threads_atomic__load_intptr(void)
+{
+	intptr_t value = 1;
+	cl_assert_equal_i((intptr_t)git_atomic_load(value), 1);
+}