whitespace: add tab-in-indent error class

Some projects and languages use coding style where no tab character is used to
indent the lines.

This only adds support and documentation for "apply --whitespace=warn" and
"diff --check"; later patches add "apply --whitespace=fix" and tests.

Signed-off-by: Chris Webb <chris@arachsys.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index 6dcb100a6..030af327f 100644
--- a/cache.h
+++ b/cache.h
@@ -1040,6 +1040,7 @@ void shift_tree_by(const unsigned char *, const unsigned char *, unsigned char *
 #define WS_INDENT_WITH_NON_TAB	04
 #define WS_CR_AT_EOL           010
 #define WS_BLANK_AT_EOF        020
+#define WS_TAB_IN_INDENT       040
 #define WS_TRAILING_SPACE      (WS_BLANK_AT_EOL|WS_BLANK_AT_EOF)
 #define WS_DEFAULT_RULE (WS_TRAILING_SPACE|WS_SPACE_BEFORE_TAB)
 extern unsigned whitespace_rule_cfg;