diff --no-index: refuse to compare stdin to a directory
When the user runs git diff --no-index file directory we follow the behavior of POSIX diff and rewrite the arguments as git diff --no-index file directory/file Doing that when "file" is "-" (which means "read from stdin") does not make sense so we should error out if the user asks us to compare "-" to a directory. This matches the behavior of GNU diff and diff on *BSD. Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Phillip Wood committed
Jul 5, 2023 at 20:49 UTC
498198453dbb8ae46becbc83a1ef0979a0eb805d
2 files changed
+12
-5
diff-no-index.c
+7
-5
@@ -218,11 +218,13 @@ static void fixup_paths(const char **path, struct strbuf *replacement)
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{
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unsigned int isdir0, isdir1;
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- if (path[0] == file_from_standard_input ||
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- path[1] == file_from_standard_input)
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- return;
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- isdir0 = is_directory(path[0]);
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- isdir1 = is_directory(path[1]);
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+ isdir0 = path[0] != file_from_standard_input && is_directory(path[0]);
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+ isdir1 = path[1] != file_from_standard_input && is_directory(path[1]);
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+
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+ if ((path[0] == file_from_standard_input && isdir1) ||
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+ (isdir0 && path[1] == file_from_standard_input))
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+ die(_("cannot compare stdin to a directory"));
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+
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if (isdir0 == isdir1)
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return;
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if (isdir0) {
t/t4053-diff-no-index.sh
+5
@@ -205,4 +205,9 @@ test_expect_success POSIXPERM,SYMLINKS 'diff --no-index normalizes: mode not lik
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test_cmp expected actual
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'
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+test_expect_success 'diff --no-index refuses to diff stdin and a directory' '
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+ test_must_fail git diff --no-index -- - a </dev/null 2>err &&
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+ grep "fatal: cannot compare stdin to a directory" err
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+'
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+
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test_done