From 6ce8fe3c0fa7725e77d6ea61557bcec65d6cdb34 Mon Sep 17 00:00:00 2001
From: Beaky2000 <johnnyjo@gmail.com>
Date: Sun, 17 Apr 2016 22:09:49 +0200
Subject: [PATCH] Fixed a bug which caused printing of floats larger than 100
 in the CLI to crash

---
 src/main/common/typeconversion.c |  5 +++++
 src/main/common/typeconversion.h | 10 ++++++++++
 src/main/io/serial_cli.c         |  2 +-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/main/common/typeconversion.c b/src/main/common/typeconversion.c
index 4e3f8b4c2e..3a3730fd56 100644
--- a/src/main/common/typeconversion.c
+++ b/src/main/common/typeconversion.c
@@ -144,6 +144,11 @@ char *itoa(int i, char *a, int base)
 
 #endif
 
+/* Note: the floatString must be at least 13 bytes long to cover all cases.
+ * This includes up to 10 digits (32 bit ints can hold numbers up to 10
+ * digits long) + the decimal point + negative sign or space + null
+ * terminator.
+ */
 char *ftoa(float x, char *floatString)
 {
     int32_t value;
diff --git a/src/main/common/typeconversion.h b/src/main/common/typeconversion.h
index 62b437875b..f2811d65ba 100644
--- a/src/main/common/typeconversion.h
+++ b/src/main/common/typeconversion.h
@@ -21,7 +21,17 @@ void li2a(long num, char *bf);
 void ui2a(unsigned int num, unsigned int base, int uc, char *bf);
 void i2a(int num, char *bf);
 char a2i(char ch, const char **src, int base, int *nump);
+
+/* Simple conversion of a float to a string. Will display completely
+ * inaccurate results for floats larger than about 2.15E6 (2^31 / 1000)
+ * (same thing for negative values < -2.15E6).
+ * Will always display 3 decimals, so anything smaller than 1E-3 will
+ * not be displayed.
+ * The floatString will be filled in with the result and will be
+ * returned. It must be at least 13 bytes in length to cover all cases!
+ */
 char *ftoa(float x, char *floatString);
+
 float fastA2F(const char *p);
 
 #ifndef HAVE_ITOA_FUNCTION
diff --git a/src/main/io/serial_cli.c b/src/main/io/serial_cli.c
index 7106a99fb7..8f009328f4 100644
--- a/src/main/io/serial_cli.c
+++ b/src/main/io/serial_cli.c
@@ -2446,7 +2446,7 @@ static void cliWrite(uint8_t ch)
 static void cliPrintVar(const clivalue_t *var, uint32_t full)
 {
     int32_t value = 0;
-    char buf[8];
+    char buf[13];
 
     void *ptr = var->ptr;
     if ((var->type & VALUE_SECTION_MASK) == PROFILE_VALUE) {