Merge branch 'vr/help-per-platform'

We used to always default to "man" format even on platforms where
"man" viewer is not widely available.

* vr/help-per-platform:
  help: use HTML as the default help format on Windows
diff --git a/Makefile b/Makefile
index 62de0b4..f62ca2a 100644
--- a/Makefile
+++ b/Makefile
@@ -299,6 +299,10 @@
 #
 # Define GIT_USER_AGENT if you want to change how git identifies itself during
 # network interactions.  The default is "git/$(GIT_VERSION)".
+#
+# 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
@@ -1242,6 +1246,7 @@
 	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
@@ -1926,6 +1931,10 @@
 GIT_USER_AGENT_CQ_SQ = $(subst ','\'',$(GIT_USER_AGENT_CQ))
 BASIC_CFLAGS += -DGIT_USER_AGENT='$(GIT_USER_AGENT_CQ_SQ)'
 
+ifdef DEFAULT_HELP_FORMAT
+BASIC_CFLAGS += -DDEFAULT_HELP_FORMAT='"$(DEFAULT_HELP_FORMAT)"'
+endif
+
 ALL_CFLAGS += $(BASIC_CFLAGS)
 ALL_LDFLAGS += $(BASIC_LDFLAGS)