fill_sha1_file: write "boring" characters

This function forms a sha1 as "xx/yyyy...", but skips over
the slot for the slash rather than writing it, leaving it to
the caller to do so. It also does not bother to put in a
trailing NUL, even though every caller would want it (we're
forming a path which by definition is not a directory, so
the only thing to do with it is feed it to a system call).

Let's make the lives of our callers easier by just writing
out the internal "/" and the NUL.

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

sha1_file.c

@@ -178,10 +178,12 @@ static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
 	for (i = 0; i < 20; i++) {
 		static char hex[] = "0123456789abcdef";
 		unsigned int val = sha1[i];
-		char *pos = pathbuf + i*2 + (i > 0);
-		*pos++ = hex[val >> 4];
-		*pos = hex[val & 0xf];
+		*pathbuf++ = hex[val >> 4];
+		*pathbuf++ = hex[val & 0xf];
+		if (!i)
+			*pathbuf++ = '/';
 	}
+	*pathbuf = '\0';
 }
 
 const char *sha1_file_name(const unsigned char *sha1)
@@ -198,8 +200,6 @@ const char *sha1_file_name(const unsigned char *sha1)
 		die("insanely long object directory %s", objdir);
 	memcpy(buf, objdir, len);
 	buf[len] = '/';
-	buf[len+3] = '/';
-	buf[len+42] = '\0';
 	fill_sha1_path(buf + len + 1, sha1);
 	return buf;
 }
@@ -406,8 +406,6 @@ struct alternate_object_database *alloc_alt_odb(const char *dir)
 
 	ent->name = ent->scratch + dirlen + 1;
 	ent->scratch[dirlen] = '/';
-	ent->scratch[dirlen + 3] = '/';
-	ent->scratch[entlen-1] = 0;
 
 	return ent;
 }