[PATCH] Make attributes "-diff" and "diff" work as advertized

[PATCH] Make attributes "-diff" and "diff" work as advertized

[Johannes Schindelin]

In Documentation/gitattributes.txt, it says that you can suppress
diffs by setting the attribute "-diff", and you can override the
binary detection with the attribute "diff".

Make it work.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---

	Evidently, this is on top of "next" + the funcname patches, since
	I realized it only when working on top of them.

	However, it should also apply cleanly to "master", and even 
	"maint". (The only reason I'm not doing it right now, is that I am 
	in the middle of preparing a patch pair, and doing this patch was 
	easy enough with rebase -i.)

 diff.c                   |   15 +++++++--------
 t/t4020-diff-external.sh |   12 ++++++++++++
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/diff.c b/diff.c
index 21e61af..e92db5c 100644
--- a/diff.c
+++ b/diff.c
@@ -1170,13 +1170,19 @@ static void diff_filespec_check_attr(struct diff_filespec *one)
 	one->is_binary = 0;
 	one->funcname_pattern_ident = NULL;
 
+	if (!one->data && DIFF_FILE_VALID(one))
+		diff_populate_filespec(one, 0);
+
+	if (one->data)
+		one->is_binary = buffer_is_binary(one->data, one->size);
+
 	if (!git_checkattr(one->path, 1, &attr_diff_check)) {
 		const char *value;
 
 		/* binaryness */
 		value = attr_diff_check.value;
 		if (ATTR_TRUE(value))
-			;
+			one->is_binary = 0;
 		else if (ATTR_FALSE(value))
 			one->is_binary = 1;
 
@@ -1186,13 +1192,6 @@ static void diff_filespec_check_attr(struct diff_filespec *one)
 		else
 			one->funcname_pattern_ident = value;
 	}
-
-	if (!one->data && DIFF_FILE_VALID(one))
-		diff_populate_filespec(one, 0);
-
-	if (one->data)
-		one->is_binary = buffer_is_binary(one->data, one->size);
-
 }
 
 int diff_filespec_is_binary(struct diff_filespec *one)
diff --git a/t/t4020-diff-external.sh b/t/t4020-diff-external.sh
index f0045cd..ed3bd5b 100755
--- a/t/t4020-diff-external.sh
+++ b/t/t4020-diff-external.sh
@@ -94,4 +94,16 @@ test_expect_success 'diff attribute should apply only to diff' '
 
 '
 
+test_expect_success 'no diff with -diff' '
+	echo >.gitattributes "file -diff" &&
+	git diff | grep Binary
+'
+
+echo NULZbetweenZwords | tr Z '\0' > file
+
+test_expect_success 'force diff with "diff"' '
+	echo >.gitattributes "file diff" &&
+	git diff | grep -a second
+'
+
 test_done
-- 
1.5.3.rc0.2712.g125b7f

Re: [PATCH] Make attributes "-diff" and "diff" work as advertized

[Junio C Hamano]

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

> diff --git a/diff.c b/diff.c
> index 21e61af..e92db5c 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -1170,13 +1170,19 @@ static void diff_filespec_check_attr(struct diff_filespec *one)
>  	one->is_binary = 0;
>  	one->funcname_pattern_ident = NULL;
>  
> +	if (!one->data && DIFF_FILE_VALID(one))
> +		diff_populate_filespec(one, 0);
> +
> +	if (one->data)
> +		one->is_binary = buffer_is_binary(one->data, one->size);
> +
>  	if (!git_checkattr(one->path, 1, &attr_diff_check)) {
>  		const char *value;
>  
>  		/* binaryness */
>  		value = attr_diff_check.value;
>  		if (ATTR_TRUE(value))
> -			;
> +			one->is_binary = 0;

I wanted to make sure we do not have to read data and run
buffer_is_binary() when attribute says we do not have to.  I
wonder why moving the code around makes the difference.

>  		else if (ATTR_FALSE(value))
>  			one->is_binary = 1;
>  
> @@ -1186,13 +1192,6 @@ static void diff_filespec_check_attr(struct diff_filespec *one)
>  		else
>  			one->funcname_pattern_ident = value;
>  	}
> -
> -	if (!one->data && DIFF_FILE_VALID(one))
> -		diff_populate_filespec(one, 0);
> -
> -	if (one->data)
> -		one->is_binary = buffer_is_binary(one->data, one->size);
> -
>  }

Ah, I see, because these are done unconditionally.  That was
silly of me.

Re: [PATCH] Make attributes "-diff" and "diff" work as advertized

[Johannes Schindelin]

Hi,

well, it was a quick fix. I had more on my wishlist for today, and wanted 
to be done with it quickly. The proper fix would be something like this, I 
guess (which should not be applied without the changes to t4020, of 
course):

 diff.c |   18 +++++++++++-------
 1 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/diff.c b/diff.c
index 04e7e91..e47921f 100644
--- a/diff.c
+++ b/diff.c
@@ -1113,13 +1113,13 @@ static void setup_diff_attr_check(struct git_attr_check *check)
 
 static void diff_filespec_check_attr(struct diff_filespec *one)
 {
+	int is_binary = -1;
 	struct git_attr_check attr_diff_check[2];
 
 	if (one->checked_attr)
 		return;
 
 	setup_diff_attr_check(attr_diff_check);
-	one->is_binary = 0;
 	one->hunk_header_ident = NULL;
 
 	if (!git_checkattr(one->path, ARRAY_SIZE(attr_diff_check), attr_diff_check)) {
@@ -1128,9 +1128,9 @@ static void diff_filespec_check_attr(struct diff_filespec *one)
 		/* binaryness */
 		value = attr_diff_check[0].value;
 		if (ATTR_TRUE(value))
-			;
+			is_binary = 0;
 		else if (ATTR_FALSE(value))
-			one->is_binary = 1;
+			is_binary = 1;
 
 		/* hunk header ident */
 		value = attr_diff_check[1].value;
@@ -1140,11 +1140,15 @@ static void diff_filespec_check_attr(struct diff_filespec *one)
 			one->hunk_header_ident = value;
 	}
 
-	if (!one->data && DIFF_FILE_VALID(one))
-		diff_populate_filespec(one, 0);
+	if (is_binary < 0) {
+		if (!one->data && DIFF_FILE_VALID(one))
+			diff_populate_filespec(one, 0);
 
-	if (one->data)
-		one->is_binary = buffer_is_binary(one->data, one->size);
+		if (one->data)
+			one->is_binary =
+				buffer_is_binary(one->data, one->size);
+	} else
+		one->is_binary = is_binary;
 
 }