[PATCH 1/2] credential: let helpers tell us to quit
When we are trying to fill a credential, we loop over the set of defined credential-helpers, then fall back to running askpass, and then finally prompt on the terminal. Helpers which cannot find a credential are free to tell us nothing, but they cannot currently ask us to stop prompting.
This patch lets them provide a "quit" attribute, which asks us to stop the process entirely (avoiding running more helpers, as well as the askpass/terminal prompt).
This has a few possible uses:
1. A helper which prompts the user itself (e.g., in a
dialog) can provide a "cancel" button to the user to
stop further prompts. 2. Some helpers may know that prompting cannot possibly
work. For example, if their role is to broker a ticket
from an external auth system and that auth system
cannot be contacted, there is no point in continuing
(we need a ticket to authenticate, and the user cannot
provide one by typing it in).Signed-off-by: Jeff King <peff@peff.net>
---
+cc spearce, as I recall that you may do something similar to the second
scenario (and this would prevent annoying useless prompts when the
helper fails).
Documentation/technical/api-credentials.txt | 5 ++++-
credential.c | 5 +++++
credential.h | 1 +
t/t0300-credentials.sh | 9 +++++++++
4 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/Documentation/technical/api-credentials.txt b/Documentation/technical/api-credentials.txt
index c1b42a4..e44426d 100644
--- a/Documentation/technical/api-credentials.txt
+++ b/Documentation/technical/api-credentials.txt
@@ -248,7 +248,10 @@ FORMAT` in linkgit:git-credential[7] for a detailed specification).
For a `get` operation, the helper should produce a list of attributes
on stdout in the same format. A helper is free to produce a subset, or
even no values at all if it has nothing useful to provide. Any provided
-attributes will overwrite those already known about by Git.
+attributes will overwrite those already known about by Git. If a helper
+outputs a `quit` attribute with a value of `true` or `1`, no further
+helpers will be consulted, nor will the user be prompted (if no
+credential has been provided, the operation will then fail).
For a `store` or `erase` operation, the helper's output is ignored.
If it fails to perform the requested operation, it may complain to
diff --git a/credential.c b/credential.c
index 1886ea5..b146ad8 100644
--- a/credential.c
+++ b/credential.c
@@ -173,6 +173,8 @@ int credential_read(struct credential *c, FILE *fp)
c->path = xstrdup(value);
} else if (!strcmp(key, "url")) {
credential_from_url(c, value);
+ } else if (!strcmp(key, "quit")) {
+ c->quit = !!git_config_bool("quit", value);
}
/*
* Ignore other lines; we don't know what they mean, but
@@ -274,6 +276,9 @@ void credential_fill(struct credential *c)
credential_do(c, c->helpers.items[i].string, "get");
if (c->username && c->password)
return;
+ if (c->quit)
+ die("credential helper '%s' told us to quit",
+ c->helpers.items[i].string);
}
credential_getpass(c);
diff --git a/credential.h b/credential.h
index 0c3e85e..6b0cd16 100644
--- a/credential.h
+++ b/credential.h
@@ -7,6 +7,7 @@ struct credential {
struct string_list helpers;
unsigned approved:1,
configured:1,
+ quit:1,
use_http_path:1;
char *username;
diff --git a/t/t0300-credentials.sh b/t/t0300-credentials.sh
index 57ea5a1..d7ef44b 100755
--- a/t/t0300-credentials.sh
+++ b/t/t0300-credentials.sh
@@ -289,4 +289,13 @@ test_expect_success 'http paths can be part of context' '
EOF
'
+test_expect_success 'helpers can abort the process' '
+ test_must_fail git \
+ -c credential.helper="!f() { echo quit=1; }; f" \
+ -c credential.helper="verbatim foo bar" \
+ credential fill >stdout &&
+ >expect &&
+ test_cmp expect stdout
+'
+
test_done
--
2.2.0.390.gf60752d
brian m. carlson
