[PATCHv2] Add the possibility to specify a default help format

[Vincent van Ravesteijn <vfr@lyx.org>]

At the moment, the default help format (i.e. the format that is chosen if
'git help xxx' is called without a help format parameter) is defined by
the switch to be 'man'. However, on different platforms the preferred
format might differ. For example, on Windows there is no man viewer, so we
would prefer html.

This patch adds the possibility to choose a default help format on
compilation by defining DEFAULT_HELP_FORMAT. If it is not specified the
default is still 'man'.

Example:
  make DEFAULT_HELP_FORMAT=info

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Vincent van Ravesteijn <vfr@lyx.org>
---
 Makefile       |    9 +++++++++
 builtin/help.c |    8 +++++++-
 2 files changed, 16 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index 4592f1f..9df6213 100644
--- a/Makefile
+++ b/Makefile
@@ -296,6 +296,10 @@ all::
 # the diff algorithm.  It gives a nice speedup if your processor has
 # fast unaligned word loads.  Does NOT work on big-endian systems!
 # Enabled by default on x86_64.
+#
+# Define DEFAULT_HELP_FORMAT to "man", "info" or "html" 
+# (defaults to "man") if you want to have a different default when
+# "git help" is called without a parameter specifying the format.
 
 GIT-VERSION-FILE: FORCE
 	@$(SHELL_PATH) ./GIT-VERSION-GEN
@@ -1236,6 +1240,7 @@ ifeq ($(uname_S),Windows)
 	BLK_SHA1 = YesPlease
 	NO_POSIX_GOODIES = UnfortunatelyYes
 	NATIVE_CRLF = YesPlease
+	DEFAULT_HELP_FORMAT = html
 
 	CC = compat/vcbuild/scripts/clink.pl
 	AR = compat/vcbuild/scripts/lib.pl
@@ -1915,6 +1920,10 @@ SHELL_PATH_CQ_SQ = $(subst ','\'',$(SHELL_PATH_CQ))
 BASIC_CFLAGS += -DSHELL_PATH='$(SHELL_PATH_CQ_SQ)'
 endif
 
+ifdef DEFAULT_HELP_FORMAT
+BASIC_CFLAGS += -DDEFAULT_HELP_FORMAT='"$(DEFAULT_HELP_FORMAT)"'
+endif
+
 ALL_CFLAGS += $(BASIC_CFLAGS)
 ALL_LDFLAGS += $(BASIC_LDFLAGS)
 
diff --git a/builtin/help.c b/builtin/help.c
index 43d3c84..536d4fd 100644
--- a/builtin/help.c
+++ b/builtin/help.c
@@ -12,6 +12,10 @@
 #include "column.h"
 #include "help.h"
 
+#ifndef DEFAULT_HELP_FORMAT
+#define DEFAULT_HELP_FORMAT "man"
+#endif
+
 static struct man_viewer_list {
 	struct man_viewer_list *next;
 	char name[FLEX_ARRAY];
@@ -445,7 +449,9 @@ int cmd_help(int argc, const char **argv, const char *prefix)
 	setup_git_directory_gently(&nongit);
 	git_config(git_help_config, NULL);
 
-	if (parsed_help_format != HELP_FORMAT_NONE)
+	if (parsed_help_format == HELP_FORMAT_NONE)
+		help_format = parse_help_format(DEFAULT_HELP_FORMAT);
+	else
 		help_format = parsed_help_format;
 
 	alias = alias_lookup(argv[0]);
-- 
1.7.9.msysgit.0