[PATCH] read-tree: Fix regression with creation of a new index file.

[PATCH] read-tree: Fix regression with creation of a new index file.

[Alexandre Julliard]

Reading the index into an empty file has been broken by
5a56da58060e50980fab0f4c38203a25440d1530, since it causes the existing
index to always be loaded first, and dies if it's an empty file:

$ GIT_INDEX_FILE=`mktemp` git read-tree master
fatal: index file smaller than expected

It breaks for instance committing from git.el. This patch reverts to the
previous behavior of only loading the index when merging it.

Signed-off-by: Alexandre Julliard <julliard@winehq.org>
---
 builtin-read-tree.c            |   10 ++++++----
 t/t1009-read-tree-new-index.sh |   25 +++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 4 deletions(-)
 create mode 100755 t/t1009-read-tree-new-index.sh

diff --git a/builtin-read-tree.c b/builtin-read-tree.c
index 9c2d634..14c836b 100644
--- a/builtin-read-tree.c
+++ b/builtin-read-tree.c
@@ -113,13 +113,15 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 	argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 			     read_tree_usage, 0);
 
-	if (read_cache_unmerged() && (opts.prefix || opts.merge))
-		die("You need to resolve your current index first");
-
 	prefix_set = opts.prefix ? 1 : 0;
 	if (1 < opts.merge + opts.reset + prefix_set)
 		die("Which one? -m, --reset, or --prefix?");
-	stage = opts.merge = (opts.reset || opts.merge || prefix_set);
+
+	if (opts.reset || opts.merge || opts.prefix) {
+		if (read_cache_unmerged() && (opts.prefix || opts.merge))
+			die("You need to resolve your current index first");
+		stage = opts.merge = 1;
+	}
 
 	for (i = 0; i < argc; i++) {
 		const char *arg = argv[i];
diff --git a/t/t1009-read-tree-new-index.sh b/t/t1009-read-tree-new-index.sh
new file mode 100755
index 0000000..59b3aa4
--- /dev/null
+++ b/t/t1009-read-tree-new-index.sh
@@ -0,0 +1,25 @@
+#!/bin/sh
+
+test_description='test read-tree into a fresh index file'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+	echo one >a &&
+	git add a &&
+	git commit -m initial
+'
+
+test_expect_success 'non-existent index file' '
+	rm -f new-index &&
+	GIT_INDEX_FILE=new-index git read-tree master
+'
+
+test_expect_success 'empty index file' '
+	rm -f new-index &&
+	> new-index &&
+	GIT_INDEX_FILE=new-index git read-tree master
+'
+
+test_done
+
-- 
1.6.4.181.g3f2ea.dirty

-- 
Alexandre Julliard
julliard@winehq.org

Re: [PATCH] read-tree: Fix regression with creation of a new index file.

[Johannes Schindelin]

Hi,

On Mon, 17 Aug 2009, Alexandre Julliard wrote:

> diff --git a/builtin-read-tree.c b/builtin-read-tree.c
> index 9c2d634..14c836b 100644
> --- a/builtin-read-tree.c
> +++ b/builtin-read-tree.c
> @@ -113,13 +113,15 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
>  	argc = parse_options(argc, argv, unused_prefix, read_tree_options,
>  			     read_tree_usage, 0);
>  
> -	if (read_cache_unmerged() && (opts.prefix || opts.merge))
> -		die("You need to resolve your current index first");
> -
>  	prefix_set = opts.prefix ? 1 : 0;
>  	if (1 < opts.merge + opts.reset + prefix_set)
>  		die("Which one? -m, --reset, or --prefix?");
> -	stage = opts.merge = (opts.reset || opts.merge || prefix_set);
> +
> +	if (opts.reset || opts.merge || opts.prefix) {
> +		if (read_cache_unmerged() && (opts.prefix || opts.merge))
> +			die("You need to resolve your current index first");
> +		stage = opts.merge = 1;
> +	}

Actually, this should be enough:

-- snipsnap --
diff --git a/builtin-read-tree.c b/builtin-read-tree.c
index 9c2d634..d649c56 100644
--- a/builtin-read-tree.c
+++ b/builtin-read-tree.c
@@ -113,14 +113,14 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 	argc = parse_options(argc, argv, unused_prefix, read_tree_options,
 			     read_tree_usage, 0);
 
-	if (read_cache_unmerged() && (opts.prefix || opts.merge))
-		die("You need to resolve your current index first");
-
 	prefix_set = opts.prefix ? 1 : 0;
 	if (1 < opts.merge + opts.reset + prefix_set)
 		die("Which one? -m, --reset, or --prefix?");
 	stage = opts.merge = (opts.reset || opts.merge || prefix_set);
 
+	if (opts.merge && (read_cache_unmerged() && !prefix_set && !opts.reset))
+		die("You need to resolve your current index first");
+
 	for (i = 0; i < argc; i++) {
 		const char *arg = argv[i];
 
-- 
1.6.4.313.g3d9e3

Re: [PATCH] read-tree: Fix regression with creation of a new index file.

[Stephen Boyd]

Johannes Schindelin wrote:
> diff --git a/builtin-read-tree.c b/builtin-read-tree.c
> index 9c2d634..d649c56 100644
> --- a/builtin-read-tree.c
> +++ b/builtin-read-tree.c
> @@ -113,14 +113,14 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
>  	argc = parse_options(argc, argv, unused_prefix, read_tree_options,
>  			     read_tree_usage, 0);
>  
> -	if (read_cache_unmerged() && (opts.prefix || opts.merge))
> -		die("You need to resolve your current index first");
> -
>  	prefix_set = opts.prefix ? 1 : 0;
>  	if (1 < opts.merge + opts.reset + prefix_set)
>  		die("Which one? -m, --reset, or --prefix?");
>  	stage = opts.merge = (opts.reset || opts.merge || prefix_set);
>  
> +	if (opts.merge && (read_cache_unmerged() && !prefix_set && !opts.reset))
>   

This looks more compact but I think the !prefix_set check is wrong.

Yes, we want to do read_cache_unmerged() if we're doing some sort of
merging operation. But we want to die() when either -m or --prefix is
used. Therefore, die() if we're not doing a --reset. So we might as well
just check that case and nothing else.

The original patch from Alexandre is correct, but if you want to avoid
extra nesting I suppose you could do something like the patch below.

Thanks.

---

diff --git a/builtin-read-tree.c b/builtin-read-tree.c
index 9c2d634..c6d5b49 100644
--- a/builtin-read-tree.c
+++ b/builtin-read-tree.c
@@ -113,14 +113,14 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
        argc = parse_options(argc, argv, unused_prefix, read_tree_options,
                             read_tree_usage, 0);
 
-       if (read_cache_unmerged() && (opts.prefix || opts.merge))
-               die("You need to resolve your current index first");
-
        prefix_set = opts.prefix ? 1 : 0;
        if (1 < opts.merge + opts.reset + prefix_set)
                die("Which one? -m, --reset, or --prefix?");
        stage = opts.merge = (opts.reset || opts.merge || prefix_set);
 
+       if (opts.merge && read_cache_unmerged() && !opts.reset)
+               die("You need to resolve your current index first");