Re: [PATCH 4/6] dir: move setting of nested_repo next to its actual usage

[Derrick Stolee <stolee@gmail.com>]

On 1/29/2020 5:03 PM, Elijah Newren via GitGitGadget wrote:
> From: Elijah Newren <newren@gmail.com>
> 
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
>  dir.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/dir.c b/dir.c
> index 225f0bc082..ef3307718a 100644
> --- a/dir.c
> +++ b/dir.c
> @@ -1659,7 +1659,7 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
>  	const char *dirname, int len, int baselen, int excluded,
>  	const struct pathspec *pathspec)
>  {
> -	int nested_repo = 0;
> +	int nested_repo;
>  
>  	/* The "len-1" is to strip the final '/' */
>  	switch (directory_exists_in_index(istate, dirname, len-1)) {
> @@ -1670,6 +1670,7 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
>  		return path_none;
>  
>  	case index_nonexistent:
> +		nested_repo = 0;

I had to look at this code in-full from en/fill-directory-fixes-more to
be sure that this case was the only use of nested_repo. However, I found
that this switch statement is unnecessarily complicated. By converting
the switch to multiple "if" statements, I noticed that the third case
actually has a "break" statement that can lead to the final "fourth case"
outside the switch statement.

Hopefully the patch below is a worthy replacement for this one:

-->8--

From b5c04e6e028cb6c7f9e78fbdd2182383d928fe6d Mon Sep 17 00:00:00 2001
From: Derrick Stolee <dstolee@microsoft.com>
Date: Thu, 30 Jan 2020 15:28:39 +0000
Subject: [PATCH] dir: refactor treat_directory to clarify variable scope

The nested_repo variable in treat_directory() is created and
initialized before a multi-case switch statement, but is only
used by one case. In fact, this switch is very asymmetrical,
as the first two cases are simple but the third is more
complicated than the rest of the method.

Extract the switch statement into a series of "if" statements.
This simplifies the trivial cases, while highlighting the fact
that a "break" statement in a condition of the third case
actually leads to jumping to the fourth case (after the switch).
This assists a reader who provides an initial scan to notice
there is a second way to approach the "show_other_directories"
case than simply the response from directory_exists_in_index().

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 dir.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/dir.c b/dir.c
index b460211e61..e48812efe6 100644
--- a/dir.c
+++ b/dir.c
@@ -1659,17 +1659,16 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
 	const char *dirname, int len, int baselen, int exclude,
 	const struct pathspec *pathspec)
 {
-	int nested_repo = 0;
-
 	/* The "len-1" is to strip the final '/' */
-	switch (directory_exists_in_index(istate, dirname, len-1)) {
-	case index_directory:
-		return path_recurse;
+	enum exist_status status = directory_exists_in_index(istate, dirname, len-1);
 
-	case index_gitdir:
+	if (status == index_directory)
+		return path_recurse;
+	if (status == index_gitdir)
 		return path_none;
 
-	case index_nonexistent:
+	if (status == index_nonexistent) {
+		int nested_repo = 0;
 		if ((dir->flags & DIR_SKIP_NESTED_GIT) ||
 		    !(dir->flags & DIR_NO_GITLINKS)) {
 			struct strbuf sb = STRBUF_INIT;
@@ -1682,7 +1681,7 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
 				(exclude ? path_excluded : path_untracked));
 
 		if (dir->flags & DIR_SHOW_OTHER_DIRECTORIES)
-			break;
+			goto show_other_directories;
 		if (exclude &&
 			(dir->flags & DIR_SHOW_IGNORED_TOO) &&
 			(dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING)) {
@@ -1711,7 +1710,7 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
 	}
 
 	/* This is the "show_other_directories" case */
-
+show_other_directories:
 	if (!(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
 		return exclude ? path_excluded : path_untracked;
 
-- 
2.25.0.vfs.1.1