int beargit_checkout(const char* arg, int new_branch) {
// Get the current branch
char current_branch[BRANCHNAME_SIZE];
read_string_from_file(".beargit/.current_branch", current_branch, BRANCHNAME_SIZE);
// If not detached, leave the current branch by storing the current HEAD into that branch's file...
if (strlen(current_branch)) {
char current_branch_file[BRANCHNAME_SIZE+50];
sprintf(current_branch_file, ".beargit/.branch_%s", current_branch);
fs_cp(".beargit/.prev", current_branch_file);
}
// Check whether the argument is a commit ID. If yes, we just change to detached mode
// without actually having to change into any other branch.
if (is_it_a_commit_id(arg)) {
char commit_dir[FILENAME_SIZE] = ".beargit/";
strcat(commit_dir, arg);
// ...and setting the current branch to none (i.e., detached).
write_string_to_file(".beargit/.current_branch", "");
return checkout_commit(arg);
}
// Read branches file (giving us the HEAD commit id for that branch).
int branch_exists = (get_branch_number(arg) >= 0);
// Check for errors.
if (!(!branch_exists || !new_branch)) {
fprintf(stderr, "ERROR: A branch named %s already exists.\n", arg);
return 1;
} else if (!branch_exists && !new_branch) {
fprintf(stderr, "ERROR: No branch or commit %s exists.\n", arg);
return 1;
}
// Just a better name, since we now know the argument is a branch name.
const char* branch_name = arg;
// File for the branch we are changing into.
char branch_file[BRANCHNAME_SIZE + 50] = ".beargit/.branch_";
strcat(branch_file, branch_name);
// Update the branch file if new branch is created (now it can't go wrong anymore)
if (new_branch) {
FILE* fbranches = fopen(".beargit/.branches", "a");
fprintf(fbranches, "%s\n", branch_name);
fclose(fbranches);
fs_cp(".beargit/.prev", branch_file);
}
write_string_to_file(".beargit/.current_branch", branch_name);
// Read the head commit ID of this branch.
char branch_head_commit_id[COMMIT_ID_SIZE];
read_string_from_file(branch_file, branch_head_commit_id, COMMIT_ID_SIZE);
// Check out the actual commit.
return checkout_commit(branch_head_commit_id);
}
int beargit_checkout(const char* arg, int new_branch) {
// Get the current branch
char current_branch[BRANCHNAME_SIZE];
read_string_from_file(".beargit/.current_branch", current_branch, BRANCHNAME_SIZE);
//MISTAKE 1: the second arguments should be current_branch rather than "current_branch"
// If not detached, update the current branch by storing the current HEAD into that branch's file...
// Even if we cancel later, this is still ok.
if (strlen(current_branch)) {
char current_branch_file[BRANCHNAME_SIZE+50];
sprintf(current_branch_file, ".beargit/.branch_%s", current_branch);
fs_cp(".beargit/.prev", current_branch_file);
}
// Check whether the argument is a commit ID. If yes, we just stay in detached mode
// without actually having to change into any other branch.
if (is_it_a_commit_id(arg)) {
char commit_dir[FILENAME_SIZE] = ".beargit/";
strcat(commit_dir, arg);
if (!fs_check_dir_exists(commit_dir)) {
fprintf(stderr, "ERROR: Commit %s does not exist\n", arg);
return 1;
}
// Set the current branch to none (i.e., detached).
write_string_to_file(".beargit/.current_branch", "");
return checkout_commit(arg);
}
// Just a better name, since we now know the argument is a branch name.
const char* branch_name = arg;
// Read branches file (giving us the HEAD commit id for that branch).
// branch_exists=1: exits
// branch_exists=0: not exist
int branch_exists = (get_branch_number(branch_name) >= 0);
// Check for errors.
if (!(!branch_exists || !new_branch)) {
fprintf(stderr, "ERROR: A branch named %s already exists\n", branch_name);
return 1;
//MISTAKE 2: no branch exist error should only been print if new_branch evaluate to false and branch_exist ealuate to false.
} else if (!branch_exists && !new_branch) {
fprintf(stderr, "ERROR: No branch %s exists\n", branch_name);
return 1;
}
// File for the branch we are changing into.
//MISTAKES 3: if use char* branch_file, it is only for reading, can apply strcat
//should change to char branch_file [] = " "
char branch_file[] = ".beargit/.branch_";
strcat(branch_file, branch_name);
// Update the branch file if new branch is created (now it can't go wrong anymore)
if (new_branch) {
FILE* fbranches = fopen(".beargit/.branches", "a");
fprintf(fbranches, "%s\n", branch_name);
fclose(fbranches);
fs_cp(".beargit/.prev", branch_file);
}
write_string_to_file(".beargit/.current_branch", branch_name);
// Read the head commit ID of this branch.
char branch_head_commit_id[COMMIT_ID_SIZE];
read_string_from_file(branch_file, branch_head_commit_id, COMMIT_ID_SIZE);
// Check out the actual commit.
return checkout_commit(branch_head_commit_id);
}