Allow building Git in systems without iconv

Systems using some uClibc versions do not properly support
iconv stuff. This patch allows Git to be built on those
systems by passing NO_ICONV=YesPlease to make. The only
drawback is mailinfo won't do charset conversion in those
systems.

Signed-off-by: Fernando J. Pereda <ferdy@gentoo.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Makefile

@@ -53,6 +53,8 @@ all:
 # Define NO_SOCKADDR_STORAGE if your platform does not have struct
 # sockaddr_storage.
 #
+# Define NO_ICONV if your libc does not properly support iconv.
+#
 # Define COLLISION_CHECK below if you believe that SHA1's
 # 1461501637330902918203684832716283019655932542976 hashes do not give you
 # sufficient guarantee that no collisions between objects will ever happen.
@@ -380,6 +382,10 @@ else
 endif
 endif
 
+ifdef NO_ICONV
+	ALL_CFLAGS += -DNO_ICONV
+endif
+
 ifdef PPC_SHA1
 	SHA1_HEADER = "ppc/sha1.h"
 	LIB_OBJS += ppc/sha1.o ppc/sha1ppc.o

mailinfo.c

@@ -7,7 +7,9 @@
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
+#ifndef NO_ICONV
 #include <iconv.h>
+#endif
 #include "git-compat-util.h"
 #include "cache.h"
 
@@ -469,6 +471,7 @@ static int decode_b_segment(char *in, char *ot, char *ep)
 
 static void convert_to_utf8(char *line, char *charset)
 {
+#ifndef NO_ICONV
 	char *in, *out;
 	size_t insize, outsize, nrc;
 	char outbuf[4096]; /* cheat */
@@ -501,6 +504,7 @@ static void convert_to_utf8(char *line, char *charset)
 		return;
 	*out = 0;
 	strcpy(line, outbuf);
+#endif
 }
 
 static void decode_header_bq(char *it)