More filemode cleanups for FAT on MacOS

This cleans up some additional issues.  The main change is that
on a filesystem that doesn't support mode bits, libgit2 will now
create new blobs with GIT_FILEMODE_BLOB always instead of being
at the mercy to the filesystem driver to report executable or not.
This means that if "core.filemode" lies and claims that filemode
is not supported, then we will ignore the executable bit from the
filesystem.  Previously we would have allowed it.

This adds an option to the new git_repository_reset_filesystem to
recurse through submodules if desired.  There may be other types
of APIs that would like a "recurse submodules" option, but this
one is particularly useful.

This also has a number of cleanups, etc., for related things
including trying to give better error messages when problems come
up from the filesystem.  For example, the FAT filesystem driver on
MacOS appears to return errno EINVAL if you attempt to write a
filename with invalid UTF-8 in it.  We try to capture that with a
better error message now.

1 files changed, 33 insertions, 52 deletions

diff --git a/src/fileops.c b/src/fileops.c
index be2e53ca8..63aedc6d0 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -78,11 +78,8 @@ int git_futils_creat_locked_withpath(const char *path, const mode_t dirmode, con
 int git_futils_open_ro(const char *path)
 {
 	int fd = p_open(path, O_RDONLY);
-	if (fd < 0) {
-		if (errno == ENOENT || errno == ENOTDIR)
-			fd = GIT_ENOTFOUND;
-		giterr_set(GITERR_OS, "Failed to open '%s'", path);
-	}
+	if (fd < 0)
+		return git_path_set_error(errno, path, "open");
 	return fd;
 }
 
@@ -138,7 +135,6 @@ int git_futils_readbuffer_fd(git_buf *buf, git_file fd, size_t len)
 int git_futils_readbuffer_updated(
 	git_buf *buf, const char *path, time_t *mtime, size_t *size, int *updated)
 {
-	int error = 0;
 	git_file fd;
 	struct stat st;
 	bool changed = false;
@@ -148,13 +144,8 @@ int git_futils_readbuffer_updated(
 	if (updated != NULL)
 		*updated = 0;
 
-	if (p_stat(path, &st) < 0) {
-		error = errno;
-		giterr_set(GITERR_OS, "Failed to stat '%s'", path);
-		if (error == ENOENT || error == ENOTDIR)
-			return GIT_ENOTFOUND;
-		return -1;
-	}
+	if (p_stat(path, &st) < 0)
+		return git_path_set_error(errno, path, "stat");
 
 	if (S_ISDIR(st.st_mode) || !git__is_sizet(st.st_size+1)) {
 		giterr_set(GITERR_OS, "Invalid regular file stat for '%s'", path);
@@ -441,66 +432,60 @@ static int futils__rm_first_parent(git_buf *path, const char *ceiling)
 
 static int futils__rmdir_recurs_foreach(void *opaque, git_buf *path)
 {
-	struct stat st;
 	futils__rmdir_data *data = opaque;
+	int error = data->error;
+	struct stat st;
 
-	if (data->depth > FUTILS_MAX_DEPTH) {
-		data->error =
-			futils__error_cannot_rmdir(path->ptr, "directory nesting too deep");
-	}
+	if (data->depth > FUTILS_MAX_DEPTH)
+		error = futils__error_cannot_rmdir(
+			path->ptr, "directory nesting too deep");
 
-	else if ((data->error = p_lstat_posixly(path->ptr, &st)) < 0) {
+	else if ((error = p_lstat_posixly(path->ptr, &st)) < 0) {
 		if (errno == ENOENT)
-			data->error = 0;
+			error = 0;
 		else if (errno == ENOTDIR) {
 			/* asked to remove a/b/c/d/e and a/b is a normal file */
 			if ((data->flags & GIT_RMDIR_REMOVE_BLOCKERS) != 0)
-				data->error = futils__rm_first_parent(path, data->base);
+				error = futils__rm_first_parent(path, data->base);
 			else
 				futils__error_cannot_rmdir(
 					path->ptr, "parent is not directory");
 		}
 		else
-			futils__error_cannot_rmdir(path->ptr, "cannot access");
+			error = git_path_set_error(errno, path->ptr, "rmdir");
 	}
 
 	else if (S_ISDIR(st.st_mode)) {
 		data->depth++;
 
-		{
-			int error =
-				git_path_direach(path, 0, futils__rmdir_recurs_foreach, data);
-			if (error < 0)
-				return (error == GIT_EUSER) ? data->error : error;
-		}
+		error = git_path_direach(path, 0, futils__rmdir_recurs_foreach, data);
+		if (error < 0)
+			return (error == GIT_EUSER) ? data->error : error;
 
 		data->depth--;
 
 		if (data->depth == 0 && (data->flags & GIT_RMDIR_SKIP_ROOT) != 0)
 			return data->error;
 
-		data->error = p_rmdir(path->ptr);
-
-		if (data->error < 0) {
+		if ((error = p_rmdir(path->ptr)) < 0) {
 			if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) != 0 &&
 				(errno == ENOTEMPTY || errno == EEXIST || errno == EBUSY))
-				data->error = 0;
+				error = 0;
 			else
-				futils__error_cannot_rmdir(path->ptr, NULL);
+				error = git_path_set_error(errno, path->ptr, "rmdir");
 		}
 	}
 
 	else if ((data->flags & GIT_RMDIR_REMOVE_FILES) != 0) {
-		data->error = p_unlink(path->ptr);
-
-		if (data->error < 0)
-			futils__error_cannot_rmdir(path->ptr, "cannot be removed");
+		if (p_unlink(path->ptr) < 0)
+			error = git_path_set_error(errno, path->ptr, "remove");
 	}
 
 	else if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) == 0)
-		data->error = futils__error_cannot_rmdir(path->ptr, "still present");
+		error = futils__error_cannot_rmdir(path->ptr, "still present");
 
-	return data->error;
+	data->error = error;
+	return error;
 }
 
 static int futils__rmdir_empty_parent(void *opaque, git_buf *path)
@@ -523,7 +508,7 @@ static int futils__rmdir_empty_parent(void *opaque, git_buf *path)
 			giterr_clear();
 			error = GIT_ITEROVER;
 		} else {
-			futils__error_cannot_rmdir(git_buf_cstr(path), NULL);
+			error = git_path_set_error(errno, git_buf_cstr(path), "rmdir");
 		}
 	}
 
@@ -818,11 +803,8 @@ int git_futils_cp(const char *from, const char *to, mode_t filemode)
 		return ifd;
 
 	if ((ofd = p_open(to, O_WRONLY | O_CREAT | O_EXCL, filemode)) < 0) {
-		if (errno == ENOENT || errno == ENOTDIR)
-			ofd = GIT_ENOTFOUND;
-		giterr_set(GITERR_OS, "Failed to open '%s' for writing", to);
 		p_close(ifd);
-		return ofd;
+		return git_path_set_error(errno, to, "open for writing");
 	}
 
 	return cp_by_fd(ifd, ofd, true);
@@ -905,15 +887,14 @@ static int _cp_r_callback(void *ref, git_buf *from)
 		goto exit;
 	}
 
-	if (p_lstat(info->to.ptr, &to_st) < 0) {
-		if (errno != ENOENT && errno != ENOTDIR) {
-			giterr_set(GITERR_OS,
-				"Could not access %s while copying files", info->to.ptr);
-			error = -1;
-			goto exit;
-		}
-	} else
+	if (!(error = git_path_lstat(info->to.ptr, &to_st)))
 		exists = true;
+	else if (error != GIT_ENOTFOUND)
+		goto exit;
+	else {
+		giterr_clear();
+		error = 0;
+	}
 
 	if ((error = git_path_lstat(from->ptr, &from_st)) < 0)
 		goto exit;