对于nodejs项目，我需要确定文件夹的哈希值以检查版本。实际上，我编写了一个脚本来测试我的代码（没有文件系统，直接使用git api进行测试）。但是它的工作时间只有一半。
我使用此API来获取哈希值：https://api.github.com/repos/zestedesavoir/zds-site/branches/dev
我made a Perl script version检查我的代码js代码。它返回相同的东西。我认为我的错误是在Object.values(json.tree).forEach(function (blob)中，使用text += blob.mode + " " + blob.path + "\0" + sha;的模式一定不好。我不知道为什么。
（实时演示：https://repl.it/repls/FearfulWhiteShelfware）
const crypto = require("crypto"),
fs = require("fs"),
path = require("path"),
getURL = require("./ajax.js").getURL;
const apiJSON = [];
//https://api.github.com/
const hashs = [
"8d66139b3acf78fa50e16383693a161c33b5e048",
"4ef57de8e81c8415d6da2b267872e602b1f28cfe",
"13b54c0bab5e7f7a05398d6d92e65eee2b227136",
"218a8f506fcd3076fad059ec42d4656c635a8171"
];
let loaded = 0;
const USEAPI = false; /* becarful low limit on repl.it */
for (let i = 0; i < hashs.length; i++) {
if (!USEAPI) {
apiJSON[i] = JSON.parse(fs.readFileSync(`a${i+1}.json`));
console.log(`A${i+1}:`);
getTreeSHA(apiJSON[i], false);
if (i+1 === hashs.length) {
console.log("\n\nPerl ouput:");
for (let j = 0; j < hashs.length; j++)
getTreeSHA(apiJSON[j], true);
}
} else {
getURL("/repos/zestedesavoir/zds-site/git/trees/" + hashs[i], function(json) {
loaded++; apiJSON[i] = json;
if (loaded === hashs.length) {
for (let i = 0; i < hashs.length; i++) {
console.log(`A${i+1}:`); getTreeSHA(apiJSON[i], false);
}
console.log("\n\nPerl ouput:");
for (let i = 0; i < hashs.length; i++)
getTreeSHA(apiJSON[i], true);
}
});
}
}
function getTreeSHA(json, getPattern) {
/*json.tree.sort((a, b) => { ---> not good see A3 & A4
if (a.type !== b.type)
if (a.type === "tree")
return 1;
else if (b.type === "tree")
return -1;
return a.path.charCodeAt(0) - b.path.charCodeAt(0)
});*/
let text = "";
Object.values(json.tree).forEach(function (blob) {
const sha = Buffer.from(blob.sha, "hex").toString(!getPattern ? "binary" : "hex");
text += (+blob.mode) + " " + blob.path;
// ^ https://stackoverflow.com/a/54137728
text += (!getPattern) ? ("\0" + sha) : (" " + sha + "\n");
});
if (getPattern) return console.log(text.replace(/\0/g, ""));
console.log("Original " + json.sha);
const pattern = "tree " + text.length + "\0" + text;
console.log("Actual : " + sha1(pattern));
function sha1(data) {
return crypto.createHash("sha1").update(data, "binary").digest("hex");
}
}
A1:
Original 8d66139b3acf78fa50e16383693a161c33b5e048
Actual : 8d66139b3acf78fa50e16383693a161c33b5e048
A2:
Original 4ef57de8e81c8415d6da2b267872e602b1f28cfe
Actual : c5c701b8114582e3bb2e353aac157a7febfcd33b <-- not god
A3:
Original 13b54c0bab5e7f7a05398d6d92e65eee2b227136
Actual : 13b54c0bab5e7f7a05398d6d92e65eee2b227136
A4:
Original 218a8f506fcd3076fad059ec42d4656c635a8171
Actual : 218a8f506fcd3076fad059ec42d4656c635a8171
//...
A2:
Original 4ef57de8e81c8415d6da2b267872e602b1f28cfe
Actual : 4ef57de8e81c8415d6da2b267872e602b1f28cfe
//...
{
"sha": "4ef57de8e81c8415d6da2b267872e602b1f28cfe",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/4ef57de8e81c8415d6da2b267872e602b1f28cfe",
"tree": [
{
"path": ".coveragerc",
"mode": "100644",
"type": "blob",
"sha": "449170d0faeb75182310345564fd1811c0b9fd73",
"size": 163,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/449170d0faeb75182310345564fd1811c0b9fd73"
},
{
"path": ".editorconfig",
"mode": "100644",
"type": "blob",
"sha": "75884936ea2d35b531af886acad747d4fd9b2a9e",
"size": 328,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/75884936ea2d35b531af886acad747d4fd9b2a9e"
},
{
"path": ".flake8",
"mode": "100644",
"type": "blob",
"sha": "69e872e30d30f5c7de3276d289d6aee81ccf4af7",
"size": 232,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/69e872e30d30f5c7de3276d289d6aee81ccf4af7"
},
{
"path": ".github",
"mode": "040000",
"type": "tree",
"sha": "56b49acad224fdb70fca11809f3e5a4d396cb01c",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/56b49acad224fdb70fca11809f3e5a4d396cb01c"
},
{
"path": ".gitignore",
"mode": "100644",
"type": "blob",
"sha": "4832b44b973574253cf1b59ba7a66cfc227cd699",
"size": 1439,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/4832b44b973574253cf1b59ba7a66cfc227cd699"
},
{
"path": ".jshintrc",
"mode": "100644",
"type": "blob",
"sha": "939efa02939437adece1e3a076d597b2557e36b5",
"size": 319,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/939efa02939437adece1e3a076d597b2557e36b5"
},
{
"path": ".travis.yml",
"mode": "100644",
"type": "blob",
"sha": "6b5e4f43790874e2cf9db23e964f72b99deeb0d1",
"size": 6040,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/6b5e4f43790874e2cf9db23e964f72b99deeb0d1"
},
{
"path": "AUTHORS",
"mode": "100644",
"type": "blob",
"sha": "0b92b7759ce2dd0a7cacf79b273368bb71ac5397",
"size": 197,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/0b92b7759ce2dd0a7cacf79b273368bb71ac5397"
},
{
"path": "CODE_OF_CONDUCT.md",
"mode": "100644",
"type": "blob",
"sha": "ae61c31efae6cea565e447467e4377da76125679",
"size": 2754,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/ae61c31efae6cea565e447467e4377da76125679"
},
{
"path": "CONTRIBUTING.md",
"mode": "100644",
"type": "blob",
"sha": "ac71ad378faf7fb7ae927b20d4d28a57c6085bf9",
"size": 155,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/ac71ad378faf7fb7ae927b20d4d28a57c6085bf9"
},
{
"path": "COPYING",
"mode": "100644",
"type": "blob",
"sha": "94a9ed024d3859793618152ea559a168bbcbb5e2",
"size": 35147,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/94a9ed024d3859793618152ea559a168bbcbb5e2"
},
{
"path": "Gulpfile.js",
"mode": "100644",
"type": "blob",
"sha": "5dd951ae61f0913605197fafa018f7db49549a68",
"size": 6137,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/5dd951ae61f0913605197fafa018f7db49549a68"
},
{
"path": "LICENSE",
"mode": "100644",
"type": "blob",
"sha": "8a171a155d85927b678068becd046194aea777a9",
"size": 717,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/8a171a155d85927b678068becd046194aea777a9"
},
{
"path": "Makefile",
"mode": "100644",
"type": "blob",
"sha": "cc722c2bc71dfbaa1b025c8c56245ed0fcd61739",
"size": 3829,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/cc722c2bc71dfbaa1b025c8c56245ed0fcd61739"
},
{
"path": "README.md",
"mode": "100644",
"type": "blob",
"sha": "a6a9013159a3766da62443c4be5e267435469fd9",
"size": 3280,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/a6a9013159a3766da62443c4be5e267435469fd9"
},
{
"path": "assets",
"mode": "040000",
"type": "tree",
"sha": "1846a32450eb2a7605acb55cab8206028cfb656f",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/1846a32450eb2a7605acb55cab8206028cfb656f"
},
{
"path": "doc",
"mode": "040000",
"type": "tree",
"sha": "f55b804a2b694db577b20c8e9851ad783fea8ee5",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/f55b804a2b694db577b20c8e9851ad783fea8ee5"
},
{
"path": "errors",
"mode": "040000",
"type": "tree",
"sha": "b37a18162be2bdae7382fc194f1bf2d0ab89bba3",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/b37a18162be2bdae7382fc194f1bf2d0ab89bba3"
},
{
"path": "export-assets",
"mode": "040000",
"type": "tree",
"sha": "3a8b85efa969c389ac3c5e7e6ad62206dbddcaca",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/3a8b85efa969c389ac3c5e7e6ad62206dbddcaca"
},
{
"path": "fixtures",
"mode": "040000",
"type": "tree",
"sha": "89cacb4de6feb81a962b9a992b9434cb44d3b0aa",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/89cacb4de6feb81a962b9a992b9434cb44d3b0aa"
},
{
"path": "geodata",
"mode": "040000",
"type": "tree",
"sha": "635d29035ae7528231edb9b74eb09887c22dda2a",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/635d29035ae7528231edb9b74eb09887c22dda2a"
},
{
"path": "manage.py",
"mode": "100755",
"type": "blob",
"sha": "458f6e2df8b431b9fa819c89e82cebf2e0a91260",
"size": 1536,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/458f6e2df8b431b9fa819c89e82cebf2e0a91260"
},
{
"path": "package.json",
"mode": "100644",
"type": "blob",
"sha": "02d231aa0c0fa299581be07bcece0393dc9a9e47",
"size": 1402,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/02d231aa0c0fa299581be07bcece0393dc9a9e47"
},
{
"path": "quotes.txt",
"mode": "100644",
"type": "blob",
"sha": "e8e84a048d70bc57c1f725fc12f2101a40c5dcbb",
"size": 1552,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/e8e84a048d70bc57c1f725fc12f2101a40c5dcbb"
},
{
"path": "requirements-dev.txt",
"mode": "100644",
"type": "blob",
"sha": "7297a894036fcf70a7209062bb51f45db1b71d39",
"size": 227,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/7297a894036fcf70a7209062bb51f45db1b71d39"
},
{
"path": "requirements-prod.txt",
"mode": "100644",
"type": "blob",
"sha": "2f957115bcf3794fdecf3c4848f21ae8f428c31b",
"size": 83,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/2f957115bcf3794fdecf3c4848f21ae8f428c31b"
},
{
"path": "requirements.txt",
"mode": "100644",
"type": "blob",
"sha": "805fefa566ef0d8f6a7c7e58d01fa4684078cf50",
"size": 998,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/805fefa566ef0d8f6a7c7e58d01fa4684078cf50"
},
{
"path": "robots.txt",
"mode": "100644",
"type": "blob",
"sha": "8ca70253a4bb677cb797a7b409df4c4a9c0baa67",
"size": 948,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/8ca70253a4bb677cb797a7b409df4c4a9c0baa67"
},
{
"path": "scripts",
"mode": "040000",
"type": "tree",
"sha": "f6a251faaaa14ba4fcf702cd0556675e70cc80f3",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/f6a251faaaa14ba4fcf702cd0556675e70cc80f3"
},
{
"path": "suggestions.txt",
"mode": "100644",
"type": "blob",
"sha": "5e5d11a62a00d3f1aea8f3825c8ec89860d31ad0",
"size": 285,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/5e5d11a62a00d3f1aea8f3825c8ec89860d31ad0"
},
{
"path": "templates",
"mode": "040000",
"type": "tree",
"sha": "5b6dde8b8b616ba078305584e23e55ad0c5b2299",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/5b6dde8b8b616ba078305584e23e55ad0c5b2299"
},
{
"path": "update.md",
"mode": "100644",
"type": "blob",
"sha": "734cb67218ac7ad952ffe2f816e4820427efe809",
"size": 45743,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/734cb67218ac7ad952ffe2f816e4820427efe809"
},
{
"path": "yarn.lock",
"mode": "100644",
"type": "blob",
"sha": "9fed208fbed286860cb606c9904eb3bab2b3d960",
"size": 193867,
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/blobs/9fed208fbed286860cb606c9904eb3bab2b3d960"
},
{
"path": "zds",
"mode": "040000",
"type": "tree",
"sha": "45b76aa70ad46e116c491a55def4b396b4ecba89",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/45b76aa70ad46e116c491a55def4b396b4ecba89"
},
{
"path": "zmd",
"mode": "040000",
"type": "tree",
"sha": "89289051d5d1e37ecc12629737d4fc01dd0df06e",
"url": "https://api.github.com/repos/zestedesavoir/zds-site/git/trees/89289051d5d1e37ecc12629737d4fc01dd0df06e"
}
],
"truncated": false
}
我制作了一个Perl脚本版本来检查我的代码并了解此问题。
（实时演示：https://repl.it/repls/VainPrizeDebugmonitor）
文件：
output_a1
100644 arborescence-back.rst 05392dacd107b9e2bb931c85632e115ae69c22cb
100644 featured.rst 20084355452644d3a171b54e9331485e73a897ea
100644 forum.rst 82efe44d491fbc69fb99b0fc0829ad349a11aae7
100644 gallery.rst e075f6d1fe182e595b950cc50d1c5701c6c48bb1
100644 member.rst 157a97545f397f02293a95034989f293cda00ee8
100644 pages.rst 30d85eb8babc8608a87272eb02a73685a71623c3
100644 private-message.rst 6e4872283841ddb0edf03f7535003b4cb5e2f3ce
100644 searchv2.rst a31835f3f39b77408b75548c215d06dcd776d3c2
100644 tutorialv2.rst e646fef1203c7c9b8137c6420d990fd40c1255ae
100644 utils.rst 846765fc32bafc05bb58e6b70883acf5de8ae97b
output_a2
100644 .coveragerc 449170d0faeb75182310345564fd1811c0b9fd73
100644 .editorconfig 75884936ea2d35b531af886acad747d4fd9b2a9e
100644 .flake8 69e872e30d30f5c7de3276d289d6aee81ccf4af7
40000 .github 56b49acad224fdb70fca11809f3e5a4d396cb01c
100644 .gitignore 4832b44b973574253cf1b59ba7a66cfc227cd699
100644 .jshintrc 939efa02939437adece1e3a076d597b2557e36b5
100644 .travis.yml 6b5e4f43790874e2cf9db23e964f72b99deeb0d1
100644 AUTHORS 0b92b7759ce2dd0a7cacf79b273368bb71ac5397
100644 CODE_OF_CONDUCT.md ae61c31efae6cea565e447467e4377da76125679
100644 CONTRIBUTING.md ac71ad378faf7fb7ae927b20d4d28a57c6085bf9
100644 COPYING 94a9ed024d3859793618152ea559a168bbcbb5e2
100644 Gulpfile.js 5dd951ae61f0913605197fafa018f7db49549a68
100644 LICENSE 8a171a155d85927b678068becd046194aea777a9
100644 Makefile cc722c2bc71dfbaa1b025c8c56245ed0fcd61739
100644 README.md a6a9013159a3766da62443c4be5e267435469fd9
40000 assets 1846a32450eb2a7605acb55cab8206028cfb656f
40000 doc f55b804a2b694db577b20c8e9851ad783fea8ee5
40000 errors b37a18162be2bdae7382fc194f1bf2d0ab89bba3
40000 export-assets 3a8b85efa969c389ac3c5e7e6ad62206dbddcaca
40000 fixtures 89cacb4de6feb81a962b9a992b9434cb44d3b0aa
40000 geodata 635d29035ae7528231edb9b74eb09887c22dda2a
100755 manage.py 458f6e2df8b431b9fa819c89e82cebf2e0a91260
100644 package.json 02d231aa0c0fa299581be07bcece0393dc9a9e47
100644 quotes.txt e8e84a048d70bc57c1f725fc12f2101a40c5dcbb
100644 requirements-dev.txt 7297a894036fcf70a7209062bb51f45db1b71d39
100644 requirements-prod.txt 2f957115bcf3794fdecf3c4848f21ae8f428c31b
100644 requirements.txt 805fefa566ef0d8f6a7c7e58d01fa4684078cf50
100644 robots.txt 8ca70253a4bb677cb797a7b409df4c4a9c0baa67
40000 scripts f6a251faaaa14ba4fcf702cd0556675e70cc80f3
100644 suggestions.txt 5e5d11a62a00d3f1aea8f3825c8ec89860d31ad0
40000 templates 5b6dde8b8b616ba078305584e23e55ad0c5b2299
100644 update.md 734cb67218ac7ad952ffe2f816e4820427efe809
100644 yarn.lock 9fed208fbed286860cb606c9904eb3bab2b3d960
40000 zds 45b76aa70ad46e116c491a55def4b396b4ecba89
40000 zmd 89289051d5d1e37ecc12629737d4fc01dd0df06e
output_a3
100644 Makefile fd4542fcb89018c3f97901b26992577590db1fe1
100644 make.bat f17fd5b680fc6dafdba3d1adda49389de4ae0b25
40000 source 7425440b50da313c10be22342f8a0f575ca64196
output_a4
40000 includes 52fe1c1c43130c011e78fc7d488ee5cd2d39fc61
100644 opensearch.xml be2e32c0f7c32a22da4c428438ae6f79965ea4ca
100644 search.html 5618f244fee4945eb799022f7e109ec8cbb2c696
Perl脚本：
XX="$(perl -sane '$F[2] =~ s/(..)/\\x$1/g ; print $F[0]." ".$F[1]."\\"."x00".$F[2]' output_a1)"
SIZE=$(echo -en "$XX" | wc -c)
echo "A1:"
echo "original: 8d66139b3acf78fa50e16383693a161c33b5e048"
echo "output :" $(echo -en "tree $SIZE\x00$XX" | sha1sum)
# ...
输出：
A1:
original: 8d66139b3acf78fa50e16383693a161c33b5e048
output : 8d66139b3acf78fa50e16383693a161c33b5e048
A2:
original: 4ef57de8e81c8415d6da2b267872e602b1f28cfe
output : c5c701b8114582e3bb2e353aac157a7febfcd33b
A3:
original: 13b54c0bab5e7f7a05398d6d92e65eee2b227136
output : 13b54c0bab5e7f7a05398d6d92e65eee2b227136
A4:
original: 218a8f506fcd3076fad059ec42d4656c635a8171
output : 218a8f506fcd3076fad059ec42d4656c635a8171
然后我们看到我的JS和Perl脚本返回相同的内容。就是说，我的模式格式不正确，我不知道为什么。
答案 0 :(得分：11)
您的代码包含一个问题，但是修复它并不能消除A2情况下的差异。
用于计算树上哈希值的官方git算法从模式字段中删除前导零。在您的示例中，该字段包含值100644和040000，而git将其记录为40000。
证明：
$ git cat-file tree 4ef57de8e81c8415d6da2b267872e602b1f28cfe|hexdump -C
00000000 31 30 30 36 34 34 20 2e 63 6f 76 65 72 61 67 65 |100644 .coverage|
00000010 72 63 00 44 91 70 d0 fa eb 75 18 23 10 34 55 64 |rc.D.p...u.#.4Ud|
00000020 fd 18 11 c0 b9 fd 73 31 30 30 36 34 34 20 2e 65 |......s100644 .e|
00000030 64 69 74 6f 72 63 6f 6e 66 69 67 00 75 88 49 36 |ditorconfig.u.I6|
00000040 ea 2d 35 b5 31 af 88 6a ca d7 47 d4 fd 9b 2a 9e |.-5.1..j..G...*.|
00000050 31 30 30 36 34 34 20 2e 66 6c 61 6b 65 38 00 69 |100644 .flake8.i|
00000060 e8 72 e3 0d 30 f5 c7 de 32 76 d2 89 d6 ae e8 1c |.r..0...2v......|
00000070 cf 4a f7 34 30 30 30 30 20 2e 67 69 74 68 75 62 |.J.40000 .github|
... ^^^^^
... !!!!!
但是在您的perl脚本中添加去除前导零 1 仍然不能解决A2情况（尽管计算出的哈希值有所变化，但仍与预期的不同）：
$ cat main.sh
XX="$(perl -sane '$F[2] =~ s/(..)/\\x$1/g ; $F[0] =~ s/^0+//g ; print $F[0]." ".$F[1]."\\"."x00".$F[2]' output_a1)"
SIZE=$(echo -en "$XX" | wc -c)
echo "original: 8d66139b3acf78fa50e16383693a161c33b5e048 output:"
echo -en "tree $SIZE\x00$XX" | sha1sum
XX="$(perl -sane '$F[2] =~ s/(..)/\\x$1/g ; $F[0] =~ s/^0+//g ; print $F[0]." ".$F[1]."\\"."x00".$F[2]' output_a2)"
SIZE=$(echo -en "$XX" | wc -c)
echo "original: 4ef57de8e81c8415d6da2b267872e602b1f28cfe output:"
echo -en "tree $SIZE\x00$XX" | sha1sum
$ ./main.sh
original: 8d66139b3acf78fa50e16383693a161c33b5e048 output:
8d66139b3acf78fa50e16383693a161c33b5e048 -
original: 4ef57de8e81c8415d6da2b267872e602b1f28cfe output:
c5c701b8114582e3bb2e353aac157a7febfcd33b -
解释是A2哈希 4ef57de8e81c8415d6da2b267872e602b1f28cfe 指向提交对象而不是树。该提交对象依次引用哈希为 c5c701b8114582e3bb2e353aac157a7febfcd33b 的树，该树正是由固定代码计算的值：
$ git cat-file -t 4ef57de8e81c8415d6da2b267872e602b1f28cfe
commit
$ git cat-file -p 4ef57de8e81c8415d6da2b267872e602b1f28cfe
tree c5c701b8114582e3bb2e353aac157a7febfcd33b
parent 502a88b41161ec7dbff0862e3d805db397caf366
...
如果您使用A2查询树，而不是首先没有问题的提交哈希（try this）。
GitHub API的一个可争论的问题是它默默地将提交哈希解析为基础树，而不是返回错误或在响应中包括发生了什么的指示（例如，通过设置{{1 }}字段，而不是查询值。
1 在一种情况下，当模式字段仅由零组成时，快速和肮脏的修复将无法正常工作。在这种情况下，模式字段将被完全擦除，而不是被单个零代替。但是，这种情况在实践中不会发生，因为git根本无法访问具有这种模式值的对象。