advice: add --no-advice global option

Advice hints must be disabled individually by setting the relevant
advice.* variables to false in the Git configuration. For server-side
and scripted usages of Git where hints can be a hindrance, it can be
cumbersome to maintain configuration to ensure all advice hints are
disabled in perpetuity. This is a particular concern in tests, where
new or changed hints can result in failed assertions.

Add a --no-advice global option to disable all advice hints from being
displayed. This is independent of the toggles for individual advice
hints. Use an internal environment variable (GIT_ADVICE) to ensure this
configuration is propagated to the usage site, even if it executes in a
subprocess.

Signed-off-by: James Liu <james@jamesliu.io>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/environment.h b/environment.h
index 05fd94d7be..0b2d457f07 100644
--- a/environment.h
+++ b/environment.h
@@ -58,6 +58,13 @@ const char *getenv_safe(struct strvec *argv, const char *name);
 #define GIT_ATTR_SOURCE_ENVIRONMENT "GIT_ATTR_SOURCE"
 
 /*
+ * Environment variable used to propagate the --no-advice global option to the
+ * advice_enabled() helper, even when run in a subprocess.
+ * This is an internal variable that should not be set by the user.
+ */
+#define GIT_ADVICE_ENVIRONMENT "GIT_ADVICE"
+
+/*
  * Environment variable used in handshaking the wire protocol.
  * Contains a colon ':' separated list of keys with optional values
  * 'key[=value]'.  Presence of unknown keys and values must be