userdiff: require explicitly allowing textconv

Diffs that have been produced with textconv almost certainly
cannot be applied, so we want to be careful not to generate
them in things like format-patch.

This introduces a new diff options, ALLOW_TEXTCONV, which
controls this behavior. It is off by default, but is
explicitly turned on for the "log" family of commands, as
well as the "diff" porcelain (but not diff-* plumbing).

Because both text conversion and external diffing are
controlled by these diff options, we can get rid of the
"plumbing versus porcelain" distinction when reading the
config. This was an attempt to control the same thing, but
suffered from being too coarse-grained.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 9 deletions

diff --git a/userdiff.c b/userdiff.c
index d95257a..3681062 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -120,7 +120,7 @@ static int parse_tristate(int *b, const char *k, const char *v)
 	return 1;
 }
 
-int userdiff_config_basic(const char *k, const char *v)
+int userdiff_config(const char *k, const char *v)
 {
 	struct userdiff_driver *drv;
 
@@ -130,14 +130,6 @@ int userdiff_config_basic(const char *k, const char *v)
 		return parse_funcname(&drv->funcname, k, v, REG_EXTENDED);
 	if ((drv = parse_driver(k, v, "binary")))
 		return parse_tristate(&drv->binary, k, v);
-
-	return 0;
-}
-
-int userdiff_config_porcelain(const char *k, const char *v)
-{
-	struct userdiff_driver *drv;
-
 	if ((drv = parse_driver(k, v, "command")))
 		return parse_string(&drv->external, k, v);
 	if ((drv = parse_driver(k, v, "textconv")))