Merge pull request #1892 from libgit2/ntk/topic/index_read

Make git_index_read() cope with external additions and removals of the index file

3 files changed, 64 insertions, 10 deletions

diff --git a/include/git2/index.h b/include/git2/index.h
index 131d04945..8064a62ff 100644
--- a/include/git2/index.h
+++ b/include/git2/index.h
@@ -225,6 +225,9 @@ GIT_EXTERN(int) git_index_set_caps(git_index *index, unsigned int caps);
  * Update the contents of an existing index object in memory
  * by reading from the hard disk.
  *
+ * If the file doesn't exist on the filesystem, the index
+ * will be cleared from its current content.
+ *
  * @param index an existing index object
  * @return 0 or an error code
  */
diff --git a/src/index.c b/src/index.c
index 21a8d31d1..c923f1675 100644
--- a/src/index.c
+++ b/src/index.c
@@ -461,9 +461,10 @@ int git_index_read(git_index *index)
 		return create_index_error(-1,
 			"Failed to read index: The index is in-memory only");
 
-	if (!index->on_disk || git_path_exists(index->index_file_path) == false) {
+	index->on_disk = git_path_exists(index->index_file_path);
+
+	if (!index->on_disk) {
 		git_index_clear(index);
-		index->on_disk = 0;
 		return 0;
 	}
 
diff --git a/tests-clar/index/tests.c b/tests-clar/index/tests.c
index 9090d4d8a..009d393d7 100644
--- a/tests-clar/index/tests.c
+++ b/tests-clar/index/tests.c
@@ -99,11 +99,11 @@ void test_index_tests__default_test_index(void)
    entries = (git_index_entry **)index->entries.contents;
 
    for (i = 0; i < ARRAY_SIZE(test_entries); ++i) {
-      git_index_entry *e = entries[test_entries[i].index];
+		git_index_entry *e = entries[test_entries[i].index];
 
-      cl_assert_equal_s(e->path, test_entries[i].path);
-      cl_assert(e->mtime.seconds == test_entries[i].mtime);
-      cl_assert(e->file_size == test_entries[i].file_size);
+		cl_assert_equal_s(e->path, test_entries[i].path);
+		cl_assert(e->mtime.seconds == test_entries[i].mtime);
+		cl_assert(e->file_size == test_entries[i].file_size);
    }
 
    git_index_free(index);
@@ -131,10 +131,10 @@ void test_index_tests__find_in_existing(void)
    cl_git_pass(git_index_open(&index, TEST_INDEX_PATH));
 
    for (i = 0; i < ARRAY_SIZE(test_entries); ++i) {
-	  size_t idx;
+		size_t idx;
 
-	  cl_assert(!git_index_find(&idx, index, test_entries[i].path));
-	  cl_assert(idx == test_entries[i].index);
+		cl_assert(!git_index_find(&idx, index, test_entries[i].path));
+		cl_assert(idx == test_entries[i].index);
    }
 
    git_index_free(index);
@@ -148,7 +148,7 @@ void test_index_tests__find_in_empty(void)
    cl_git_pass(git_index_open(&index, "fake-index"));
 
    for (i = 0; i < ARRAY_SIZE(test_entries); ++i) {
-      cl_assert(GIT_ENOTFOUND == git_index_find(NULL, index, test_entries[i].path));
+		cl_assert(GIT_ENOTFOUND == git_index_find(NULL, index, test_entries[i].path));
    }
 
    git_index_free(index);
@@ -484,3 +484,53 @@ void test_index_tests__elocked(void)
 	git_index_free(index);
 	git_repository_free(repo);
 }
+
+void test_index_tests__reload_from_disk(void)
+{
+	git_repository *repo;
+	git_index *read_index;
+	git_index *write_index;
+
+	cl_set_cleanup(&cleanup_myrepo, NULL);
+
+	cl_git_pass(git_futils_mkdir("./myrepo", NULL, 0777, GIT_MKDIR_PATH));
+	cl_git_mkfile("./myrepo/a.txt", "a\n");
+	cl_git_mkfile("./myrepo/b.txt", "b\n");
+
+	cl_git_pass(git_repository_init(&repo, "./myrepo", 0));
+	cl_git_pass(git_repository_index(&write_index, repo));
+	cl_assert_equal_i(false, write_index->on_disk);
+
+	cl_git_pass(git_index_open(&read_index, write_index->index_file_path));
+	cl_assert_equal_i(false, read_index->on_disk);
+
+	/* Stage two new files agaisnt the write_index */
+	cl_git_pass(git_index_add_bypath(write_index, "a.txt"));
+	cl_git_pass(git_index_add_bypath(write_index, "b.txt"));
+
+	cl_assert_equal_sz(2, git_index_entrycount(write_index));
+
+	/* Persist the index changes to disk */
+	cl_git_pass(git_index_write(write_index));
+	cl_assert_equal_i(true, write_index->on_disk);
+
+	/* Sync the changes back into the read_index */
+	cl_assert_equal_sz(0, git_index_entrycount(read_index));
+
+	cl_git_pass(git_index_read(read_index));
+	cl_assert_equal_i(true, read_index->on_disk);
+
+	cl_assert_equal_sz(2, git_index_entrycount(read_index));
+
+	/* Remove the index file from the filesystem */
+	cl_git_pass(p_unlink(write_index->index_file_path));
+
+	/* Sync the changes back into the read_index */
+	cl_git_pass(git_index_read(read_index));
+	cl_assert_equal_i(false, read_index->on_disk);
+	cl_assert_equal_sz(0, git_index_entrycount(read_index));
+
+	git_index_free(read_index);
+	git_index_free(write_index);
+	git_repository_free(repo);
+}