verify_filename(): handle backslashes in "wildcards are pathspecs" rule

Commit 28fcc0b71a (pathspec: avoid the need of "--" when wildcard is used, 2015-05-02) allowed: git rev-parse '*.c' without the double-dash. But the rule it uses to check for wildcards actually looks for any glob special. This is overly liberal, as it means that a pattern that doesn't actually do any wildcard matching, like "a\b", will be considered a pathspec. If you do have such a file on disk, that's presumably what you wanted. But if you don't, the results are confusing: rather than say "there's no such path a\b", we'll quietly accept it as a pathspec which very likely matches nothing (or at least not what you intended). Likewise, looking for path "a\*b" doesn't expand the search at all; it would only find a single entry, "a*b". This commit switches the rule to trigger only when glob metacharacters would expand the search, meaning both of those cases will now report an error (you can still disambiguate using "--", of course; we're just tightening the DWIM heuristic). Note that we didn't test the original feature in 28fcc0b71a at all. So this patch not only tests for these corner cases, but also adds a regression test for the existing behavior. Reported-by: David Burström <davidburstrom@spotify.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Jan 24, 2020 at 19:00 UTC 39e21c6ef5221a1dcb8a241f60d7e91d59bd6627

2 files changed +34 -3

setup.c

+20 -3

@@ -197,9 +197,26 @@ static void NORETURN die_verify_filename(struct repository *r,

197 */

198 static int looks_like_pathspec(const char *arg)

199 {

200 - /* anything with a wildcard character */

201 - if (!no_wildcard(arg))

202 - return 1;

200 + const char *p;

201 + int escaped = 0;

202 +

203 + /*

204 + * Wildcard characters imply the user is looking to match pathspecs

205 + * that aren't in the filesystem. Note that this doesn't include

206 + * backslash even though it's a glob special; by itself it doesn't

207 + * cause any increase in the match. Likewise ignore backslash-escaped

208 + * wildcard characters.

209 + */

210 + for (p = arg; *p; p++) {

211 + if (escaped) {

212 + escaped = 0;

213 + } else if (is_glob_special(*p)) {

214 + if (*p == '\\')

215 + escaped = 1;

216 + else

217 + return 1;

218 + }

219 + }

220

221 /* long-form pathspec magic */

222 if (starts_with(arg, ":("))

t/t1506-rev-parse-diagnosis.sh

+14

@@ -222,4 +222,18 @@ test_expect_success 'reject Nth ancestor if N is too high' '

222 test_must_fail git rev-parse HEAD~100000000000000000000000000000000

223 '

224

225 +test_expect_success 'pathspecs with wildcards are not ambiguous' '

226 + echo "*.c" >expect &&

227 + git rev-parse "*.c" >actual &&

228 + test_cmp expect actual

229 +'

230 +

231 +test_expect_success 'backslash does not trigger wildcard rule' '

232 + test_must_fail git rev-parse "foo\\bar"

233 +'

234 +

235 +test_expect_success 'escaped char does not trigger wildcard rule' '

236 + test_must_fail git rev-parse "foo\\*bar"

237 +'

238 +

239 test_done