From 605824952c86006fad36116ffc7dc25558206749 Mon Sep 17 00:00:00 2001
From: Vikram Rajkumar <vikram@bitshares.org>
Date: Mon, 29 Jun 2015 11:46:36 -0400
Subject: [PATCH] Clean up is_valid_symbol

---
 .../chain/include/graphene/chain/config.hpp   |  6 ++-
 libraries/chain/operations.cpp                | 37 ++++++++++++-------
 2 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/libraries/chain/include/graphene/chain/config.hpp b/libraries/chain/include/graphene/chain/config.hpp
index b1e181b2..e31eead5 100644
--- a/libraries/chain/include/graphene/chain/config.hpp
+++ b/libraries/chain/include/graphene/chain/config.hpp
@@ -19,8 +19,12 @@
 
 #define GRAPHENE_SYMBOL "CORE"
 #define GRAPHENE_ADDRESS_PREFIX "GPH"
-#define GRAPHENE_MAX_SYMBOL_NAME_LENGTH 16
+
+#define GRAPHENE_MIN_SYMBOL_NAME_LENGTH 3
+#define GRAPHENE_MAX_SYMBOL_NAME_LENGTH 17
+
 #define GRAPHENE_MAX_ASSET_NAME_LENGTH 127
+
 #define GRAPHENE_MAX_SHARE_SUPPLY int64_t(1000000000000ll)
 #define GRAPHENE_MAX_PAY_RATE 10000 /* 100% */
 #define GRAPHENE_MAX_SIG_CHECK_DEPTH 2
diff --git a/libraries/chain/operations.cpp b/libraries/chain/operations.cpp
index 3a9029e0..598c7539 100644
--- a/libraries/chain/operations.cpp
+++ b/libraries/chain/operations.cpp
@@ -23,22 +23,33 @@
 namespace graphene { namespace chain {
 
 /**
- *  Valid symbols have between 3 and 17 upper case characters
- *  with at most a single "." that is not the first or last character.
+ *  Valid symbols have at most a single "." that is not the first or last character.
  */
 bool is_valid_symbol( const string& symbol )
 {
-   if( symbol.size() > 17 ) return false;
-   if( symbol.size() < 3  ) return false;
-   int dot_count = 0;
-   for( auto c : symbol )
-   {
-      if( c == '.' ) ++dot_count;
-      else if( c < 'A' || c > 'Z' ) return false;
-   }
-   if( symbol[0] == '.' || symbol[symbol.size()-1] == '.' )
-      return false;
-   return dot_count <= 1;
+    if( symbol.size() < GRAPHENE_MIN_SYMBOL_NAME_LENGTH || symbol.size() > GRAPHENE_MAX_SYMBOL_NAME_LENGTH )
+        return false;
+
+    if( symbol.front() == '.' || symbol.back() == '.' )
+        return false;
+
+    bool dot_already_present = false;
+    for( const auto c : symbol )
+    {
+        if( c == '.' )
+        {
+            if( dot_already_present )
+                return false;
+
+            dot_already_present = true;
+        }
+        else if( !isalpha( c ) || !isupper( c ) )
+        {
+            return false;
+        }
+    }
+
+    return true;
 }
 
 /**