Merge branch 'maint-1.6.0' into maint-1.6.1

* maint-1.6.0:
  base85: Make the code more obvious instead of explaining the non-obvious
  base85: encode_85() does not use the decode table
  base85 debug code: Fix length byte calculation
  checkout -m: do not try to fall back to --merge from an unborn branch
  branch: die explicitly why when calling "git branch [-a|-r] branchname".

1 files changed, 3 insertions, 11 deletions

diff --git a/base85.c b/base85.c
index b88270f908..24ddf60eb0 100644
--- a/base85.c
+++ b/base85.c
@@ -57,14 +57,8 @@ int decode_85(char *dst, const char *buffer, int len)
 		de = de85[ch];
 		if (--de < 0)
 			return error("invalid base85 alphabet %c", ch);
-		/*
-		 * Detect overflow.  The largest
-		 * 5-letter possible is "|NsC0" to
-		 * encode 0xffffffff, and "|NsC" gives
-		 * 0x03030303 at this point (i.e.
-		 * 0xffffffff = 0x03030303 * 85).
-		 */
-		if (0x03030303 < acc ||
+		/* Detect overflow. */
+		if (0xffffffff / 85 < acc ||
 		    0xffffffff - de < (acc *= 85))
 			return error("invalid base85 sequence %.5s", buffer-5);
 		acc += de;
@@ -84,8 +78,6 @@ int decode_85(char *dst, const char *buffer, int len)
 
 void encode_85(char *buf, const unsigned char *data, int bytes)
 {
-	prep_base85();
-
 	say("encode 85");
 	while (bytes) {
 		unsigned acc = 0;
@@ -118,7 +110,7 @@ int main(int ac, char **av)
 		int len = strlen(av[2]);
 		encode_85(buf, av[2], len);
 		if (len <= 26) len = len + 'A' - 1;
-		else len = len + 'a' - 26 + 1;
+		else len = len + 'a' - 26 - 1;
 		printf("encoded: %c%s\n", len, buf);
 		return 0;
 	}