From: Jeff King When we stuff config options into GIT_CONFIG_PARAMETERS, we shell-quote each one as a single unit, like: 'section.one=value1' 'section.two=value2' On the reading side, we de-quote to get the individual strings, and then parse them by splitting on the first "=" we find. This format is ambiguous, because an "=" may appear in a subsection. So the config represented in a file by both: [section "subsection=with=equals"] key = value and: [section] subsection = with=equals.key=value ends up in this flattened format like: 'section.subsection=with=equals.key=value' and we can't tell which was desired. We have traditionally resolved this by taking the first "=" we see starting from the left, meaning that we allowed arbitrary content in the value, but not in the subsection. Let's make our environment format a bit more robust by separately quoting the key and value. That turns those examples into: 'section.subsection=with=equals.key'='value' and: 'section.subsection'='with=equals.key=value' respectively, and we can tell the difference between them. We can detect which format is in use for any given element of the list based on the presence of the unquoted "=". That means we can continue to allow the old format to work to support any callers which manually used the old format, and we can even intermingle the two formats. The old format wasn't documented, and nobody was supposed to be using it. But it's likely that such callers exist in the wild, so it's nice if we can avoid breaking them. Likewise, it may be possible to trigger an older version of "git -c" that runs a script that calls into a newer version of "git -c"; that new version would see the intermingled format. This does create one complication, which is that the obvious format in the new scheme for [section] some-bool is: 'section.some-bool' with no equals. We'd mistake that for an old-style variable. And it even has the same meaning in the old style, but: [section "with=equals"] some-bool does not. It would be: 'section.with=equals=some-bool' which we'd take to mean: [section] with = equals=some-bool in the old, ambiguous style. Likewise, we can't use: 'section.some-bool'='' because that's ambiguous with an actual empty string. Instead, we'll again use the shell-quoting to give us a hint, and use: 'section.some-bool'= to show that we have no value. Note that this commit just expands the reading side. We'll start writing the new format via "git -c" in a future patch. In the meantime, the existing "git -c" tests will make sure we didn't break reading the old format. But we'll also add some explicit coverage of the two formats to make sure we continue to handle the old one after we move the writing side over. And one final note: since we're now using the shell-quoting as a semantically meaningful hint, this closes the door to us ever allowing arbitrary shell quoting, like: 'a'shell'would'be'ok'with'this'.key=value But we have never supported that (only what sq_quote() would produce), and we are probably better off keeping things simple, robust, and backwards-compatible, than trying to make it easier for humans. We'll continue not to advertise the format of the variable to users, and instead keep "git -c" as the recommended mechanism for setting config (even if we are trying to be kind not to break users who may be relying on the current undocumented format). Signed-off-by: Jeff King --- config.c | 69 +++++++++++++++++++++++++++++++++++------------ t/t1300-config.sh | 52 +++++++++++++++++++++++++++++++++++ 2 files changed, 104 insertions(+), 17 deletions(-) diff --git a/config.c b/config.c index b5475c28aa..33099a3b0d 100644 --- a/config.c +++ b/config.c @@ -544,14 +544,62 @@ int git_config_parse_parameter(const char *text, return ret; } +static int parse_config_env_list(char *env, config_fn_t fn, void *data) +{ + char *cur = env; + while (cur && *cur) { + const char *key = sq_dequote_step(cur, &cur); + if (!key) + return error(_("bogus format in %s"), + CONFIG_DATA_ENVIRONMENT); + + if (!cur || isspace(*cur)) { + /* old-style 'key=value' */ + if (git_config_parse_parameter(key, fn, data) < 0) + return -1; + } + else if (*cur == '=') { + /* new-style 'key'='value' */ + const char *value; + + cur++; + if (*cur == '\'') { + /* quoted value */ + value = sq_dequote_step(cur, &cur); + if (!value || (cur && !isspace(*cur))) { + return error(_("bogus format in %s"), + CONFIG_DATA_ENVIRONMENT); + } + } else if (!*cur || isspace(*cur)) { + /* implicit bool: 'key'= */ + value = NULL; + } else { + return error(_("bogus format in %s"), + CONFIG_DATA_ENVIRONMENT); + } + + if (config_parse_pair(key, value, fn, data) < 0) + return -1; + } + else { + /* unknown format */ + return error(_("bogus format in %s"), + CONFIG_DATA_ENVIRONMENT); + } + + if (cur) { + while (isspace(*cur)) + cur++; + } + } + return 0; +} + int git_config_from_parameters(config_fn_t fn, void *data) { const char *env = getenv(CONFIG_DATA_ENVIRONMENT); int ret = 0; char *envw; - const char **argv = NULL; - int nr = 0, alloc = 0; - int i; struct config_source source; if (!env) @@ -564,21 +612,8 @@ int git_config_from_parameters(config_fn_t fn, void *data) /* sq_dequote will write over it */ envw = xstrdup(env); + ret = parse_config_env_list(envw, fn, data); - if (sq_dequote_to_argv(envw, &argv, &nr, &alloc) < 0) { - ret = error(_("bogus format in %s"), CONFIG_DATA_ENVIRONMENT); - goto out; - } - - for (i = 0; i < nr; i++) { - if (git_config_parse_parameter(argv[i], fn, data) < 0) { - ret = -1; - goto out; - } - } - -out: - free(argv); free(envw); cf = source.prev; return ret; diff --git a/t/t1300-config.sh b/t/t1300-config.sh index 24919d5445..0063e9f059 100755 --- a/t/t1300-config.sh +++ b/t/t1300-config.sh @@ -1294,6 +1294,58 @@ test_expect_success 'git -c is not confused by empty environment' ' GIT_CONFIG_PARAMETERS="" git -c x.one=1 config --list ' +test_expect_success 'GIT_CONFIG_PARAMETERS handles old-style entries' ' + v="${SQ}key.one=foo${SQ}" && + v="$v ${SQ}key.two=bar${SQ}" && + v="$v ${SQ}key.ambiguous=section.whatever=value${SQ}" && + GIT_CONFIG_PARAMETERS=$v git config --get-regexp "key.*" >actual && + cat >expect <<-EOF && + key.one foo + key.two bar + key.ambiguous section.whatever=value + EOF + test_cmp expect actual +' + +test_expect_success 'GIT_CONFIG_PARAMETERS handles new-style entries' ' + v="${SQ}key.one${SQ}=${SQ}foo${SQ}" && + v="$v ${SQ}key.two${SQ}=${SQ}bar${SQ}" && + v="$v ${SQ}key.ambiguous=section.whatever${SQ}=${SQ}value${SQ}" && + GIT_CONFIG_PARAMETERS=$v git config --get-regexp "key.*" >actual && + cat >expect <<-EOF && + key.one foo + key.two bar + key.ambiguous=section.whatever value + EOF + test_cmp expect actual +' + +test_expect_success 'old and new-style entries can mix' ' + v="${SQ}key.oldone=oldfoo${SQ}" && + v="$v ${SQ}key.newone${SQ}=${SQ}newfoo${SQ}" && + v="$v ${SQ}key.oldtwo=oldbar${SQ}" && + v="$v ${SQ}key.newtwo${SQ}=${SQ}newbar${SQ}" && + GIT_CONFIG_PARAMETERS=$v git config --get-regexp "key.*" >actual && + cat >expect <<-EOF && + key.oldone oldfoo + key.newone newfoo + key.oldtwo oldbar + key.newtwo newbar + EOF + test_cmp expect actual +' + +test_expect_success 'old and new bools with ambiguous subsection' ' + v="${SQ}key.with=equals.oldbool${SQ}" && + v="$v ${SQ}key.with=equals.newbool${SQ}=" && + GIT_CONFIG_PARAMETERS=$v git config --get-regexp "key.*" >actual && + cat >expect <<-EOF && + key.with equals.oldbool + key.with=equals.newbool + EOF + test_cmp expect actual +' + test_expect_success 'detect bogus GIT_CONFIG_PARAMETERS' ' cat >expect <<-\EOF && env.one one -- 2.30.0