rm: loosen safety valve for empty files

If a file is different between the working tree copy, the index, and the HEAD, then we do not allow it to be deleted without --force. However, this is overly tight in the face of "git add --intent-to-add": $ git add --intent-to-add file $ : oops, I don't actually want to stage that yet $ git rm --cached file error: 'empty' has staged content different from both the file and the HEAD (use -f to force removal) $ git rm -f --cached file Unfortunately, there is currently no way to distinguish between an empty file that has been added and an "intent to add" file. The ideal behavior would be to disallow the former while allowing the latter. This patch loosens the safety valve to allow the deletion only if we are deleting the cached entry and the cached content is empty. This covers the intent-to-add situation, and assumes there is little harm in not protecting users who have legitimately added an empty file. In many cases, the file will still be empty, in which case the safety valve does not trigger anyway (since the content remains untouched in the working tree). Otherwise, we do remove the fact that no content was staged, but given that the content is by definition empty, it is not terribly difficult for a user to recreate it. However, we still document the desired behavior in the form of two tests. One checks the correct removal of an intent-to-add file. The other checks that we still disallow removal of empty files, but is marked as expect_failure to indicate this compromise. If the intent-to-add feature is ever extended to differentiate between normal empty files and intent-to-add files, then the safety valve can be re-tightened. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Oct 21, 2008 at 09:54 UTC f55527f80223178d1837bae08addc57bed76d236

4 files changed +17 -2

builtin-rm.c

+2 -1

@@ -79,7 +79,8 @@ static int check_local_mod(unsigned char *head, int index_only)

79 || hashcmp(ce->sha1, sha1))

80 staged_changes = 1;

82 - if (local_changes && staged_changes)

82 + if (local_changes && staged_changes &&

83 + !(index_only && is_empty_blob_sha1(ce->sha1)))

84 errs = error("'%s' has staged content different "

85 "from both the file and the HEAD\n"

86 "(use -f to force removal)", name);

cache.h

@@ -519,6 +519,7 @@ static inline void hashclr(unsigned char *hash)

519 {

520 memset(hash, 0, 20);

521 }

522 +extern int is_empty_blob_sha1(const unsigned char *sha1);

523

524 int git_mkstemp(char *path, size_t n, const char *template);

525

read-cache.c

+1 -1

@@ -160,7 +160,7 @@ static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)

160 return 0;

161 }

162

163 -static int is_empty_blob_sha1(const unsigned char *sha1)

163 +int is_empty_blob_sha1(const unsigned char *sha1)

164 {

165 static const unsigned char empty_blob_sha1[20] = {

166 0xe6,0x9d,0xe2,0x9b,0xb2,0xd1,0xd6,0x43,0x4b,0x8b,

t/t3600-rm.sh

+13

@@ -187,6 +187,19 @@ test_expect_success 'but with -f it should work.' '

187 test_must_fail git ls-files --error-unmatch baz

188 '

189

190 +test_expect_failure 'refuse to remove cached empty file with modifications' '

191 + touch empty &&

192 + git add empty &&

193 + echo content >empty &&

194 + test_must_fail git rm --cached empty

195 +'

196 +

197 +test_expect_success 'remove intent-to-add file without --force' '

198 + echo content >intent-to-add &&

199 + git add -N intent-to-add

200 + git rm --cached intent-to-add

201 +'

202 +

203 test_expect_success 'Recursive test setup' '

204 mkdir -p frotz &&

205 echo qfwfq >frotz/nitfol &&