From 521458908b0aef72ca9bc471ace757942fcce601 Mon Sep 17 00:00:00 2001
From: pancake <pancake@nopcode.org>
Date: Mon, 19 Dec 2016 04:27:13 +0100
Subject: [PATCH] Fix div by zero and help for $fl

---
 libr/core/cmd_help.c | 2 +-
 libr/hash/entropy.c  | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/libr/core/cmd_help.c b/libr/core/cmd_help.c
index c76439b6c0..8cf82101c8 100644
--- a/libr/core/cmd_help.c
+++ b/libr/core/cmd_help.c
@@ -463,7 +463,7 @@ static int cmd_help(void *data, const char *input) {
 			"$b", "", "block size",
 			"$B", "", "base address (aligned lowest map address)",
 			"$f", "", "jump fail address (e.g. jz 0x10 => next instruction)",
-			"$fl", "", "flag length (size) at current address (fla; pD $l @ entry0)"
+			"$fl", "", "flag length (size) at current address (fla; pD $l @ entry0)",
 			"$F", "", "current function size",
 			"$FB", "", "begin of function",
 			"$Fb", "", "address of the current basic block",
diff --git a/libr/hash/entropy.c b/libr/hash/entropy.c
index d38ec7703b..00007a0e38 100644
--- a/libr/hash/entropy.c
+++ b/libr/hash/entropy.c
@@ -16,7 +16,7 @@ static double get_px(ut8 x, const ut8 *data, ut64 size) {
                         count++;
 		}
 	}
-        return (double) count / size;
+        return size > 0? (double) count / size: 0;
 }
 
 R_API double r_hash_entropy(const ut8 *data, ut64 size) {
@@ -24,8 +24,9 @@ R_API double r_hash_entropy(const ut8 *data, ut64 size) {
         double h = 0, px, log2 = log (2.0);
         for (x = 0; x < 256; x++) {
                 px = get_px (x, data, size);
-                if (px > 0)
+                if (px > 0) {
                         h += -px * (log (px) / log2);
+		}
         }
         return h;
 }