Add casts for unavoidable signed/unsigned comparisons

At these code sites, it is preferable to cast rather than change
a variable's type.

src/bignum.h

@@ -117,9 +117,9 @@ public:
     {
         unsigned long n = BN_get_word(this);
         if (!BN_is_negative(this))
-            return (n > std::numeric_limits<int>::max() ? std::numeric_limits<int>::max() : n);
+            return (n > (unsigned long)std::numeric_limits<int>::max() ? std::numeric_limits<int>::max() : n);
         else
-            return (n > std::numeric_limits<int>::max() ? std::numeric_limits<int>::min() : -(int)n);
+            return (n > (unsigned long)std::numeric_limits<int>::max() ? std::numeric_limits<int>::min() : -(int)n);
     }
 
     void setint64(int64 n)

src/bitcoinrpc.cpp

@@ -999,7 +999,7 @@ Value addmultisigaddress(const Array& params, bool fHelp)
         strAccount = AccountFromValue(params[2]);
 
     // Gather public keys
-    if (nRequired < 1 || keys.size() < nRequired)
+    if ((nRequired < 1) || ((int)keys.size() < nRequired))
         throw runtime_error(
             strprintf("wrong number of keys"
                       "(got %d, need at least %d)", keys.size(), nRequired));
@@ -1331,8 +1331,10 @@ Value listtransactions(const Array& params, bool fHelp)
     }
     // ret is newest to oldest
     
-    if (nFrom > ret.size()) nFrom = ret.size();
-    if (nFrom+nCount > ret.size()) nCount = ret.size()-nFrom;
+    if (nFrom > (int)ret.size())
+        nFrom = ret.size();
+    if ((nFrom + nCount) > (int)ret.size())
+        nCount = ret.size() - nFrom;
     Array::iterator first = ret.begin();
     std::advance(first, nFrom);
     Array::iterator last = ret.begin();
@@ -2202,7 +2204,7 @@ int ReadHTTP(std::basic_istream<char>& stream, map<string, string>& mapHeadersRe
 
     // Read header
     int nLen = ReadHTTPHeader(stream, mapHeadersRet);
-    if (nLen < 0 || nLen > MAX_SIZE)
+    if (nLen < 0 || nLen > (int)MAX_SIZE)
         return 500;
 
     // Read message

src/main.cpp

@@ -376,10 +376,10 @@ int CMerkleTx::SetMerkleBranch(const CBlock* pblock)
         hashBlock = pblock->GetHash();
 
         // Locate the transaction
-        for (nIndex = 0; nIndex < pblock->vtx.size(); nIndex++)
+        for (nIndex = 0; nIndex < (int)pblock->vtx.size(); nIndex++)
             if (pblock->vtx[nIndex] == *(CTransaction*)this)
                 break;
-        if (nIndex == pblock->vtx.size())
+        if (nIndex == (int)pblock->vtx.size())
         {
             vMerkleBranch.clear();
             nIndex = -1;
@@ -2750,7 +2750,7 @@ bool ProcessMessages(CNode* pfrom)
         int nHeaderSize = vRecv.GetSerializeSize(CMessageHeader());
         if (vRecv.end() - pstart < nHeaderSize)
         {
-            if (vRecv.size() > nHeaderSize)
+            if ((int)vRecv.size() > nHeaderSize)
             {
                 printf("\n\nPROCESSMESSAGE MESSAGESTART NOT FOUND\n\n");
                 vRecv.erase(vRecv.begin(), vRecv.end() - nHeaderSize);
@@ -3084,7 +3084,7 @@ unsigned int static ScanHash_CryptoPP(char* pmidstate, char* pdata, char* phash1
         if ((nNonce & 0xffff) == 0)
         {
             nHashesDone = 0xffff+1;
-            return -1;
+            return (unsigned int) -1;
         }
     }
 }
@@ -3461,7 +3461,7 @@ void static BitcoinMiner(CWallet *pwallet)
                                             (char*)&hash, nHashesDone);
 
             // Check if something found
-            if (nNonceFound != -1)
+            if (nNonceFound != (unsigned int) -1)
             {
                 for (unsigned int i = 0; i < sizeof(hash)/4; i++)
                     ((unsigned int*)&hash)[i] = ByteReverse(((unsigned int*)&hash)[i]);

src/main.h

@@ -437,7 +437,7 @@ public:
             nBlockHeight = nBestHeight;
         if (nBlockTime == 0)
             nBlockTime = GetAdjustedTime();
-        if ((int64)nLockTime < (nLockTime < LOCKTIME_THRESHOLD ? (int64)nBlockHeight : nBlockTime))
+        if ((int64)nLockTime < ((int64)nLockTime < LOCKTIME_THRESHOLD ? (int64)nBlockHeight : nBlockTime))
             return true;
         BOOST_FOREACH(const CTxIn& txin, vin)
             if (!txin.IsFinal())

src/protocol.cpp

@@ -128,7 +128,7 @@ bool operator<(const CInv& a, const CInv& b)
 
 bool CInv::IsKnownType() const
 {
-    return (type >= 1 && type < ARRAYLEN(ppszTypeName));
+    return (type >= 1 && type < (int)ARRAYLEN(ppszTypeName));
 }
 
 const char* CInv::GetCommand() const

src/script.cpp

@@ -536,7 +536,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                         return false;
                     int n = CastToBigNum(stacktop(-1)).getint();
                     popstack(stack);
-                    if (n < 0 || n >= stack.size())
+                    if (n < 0 || n >= (int)stack.size())
                         return false;
                     valtype vch = stacktop(-n-1);
                     if (opcode == OP_ROLL)
@@ -604,9 +604,9 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     int nEnd = nBegin + CastToBigNum(stacktop(-1)).getint();
                     if (nBegin < 0 || nEnd < nBegin)
                         return false;
-                    if (nBegin > vch.size())
+                    if (nBegin > (int)vch.size())
                         nBegin = vch.size();
-                    if (nEnd > vch.size())
+                    if (nEnd > (int)vch.size())
                         nEnd = vch.size();
                     vch.erase(vch.begin() + nEnd, vch.end());
                     vch.erase(vch.begin(), vch.begin() + nBegin);
@@ -625,7 +625,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     int nSize = CastToBigNum(stacktop(-1)).getint();
                     if (nSize < 0)
                         return false;
-                    if (nSize > vch.size())
+                    if (nSize > (int)vch.size())
                         nSize = vch.size();
                     if (opcode == OP_LEFT)
                         vch.erase(vch.begin() + nSize, vch.end());

src/script.h

@@ -467,7 +467,7 @@ public:
         opcodetype opcode;
         do
         {
-            while (end() - pc >= b.size() && memcmp(&pc[0], &b[0], b.size()) == 0)
+            while (end() - pc >= (long)b.size() && memcmp(&pc[0], &b[0], b.size()) == 0)
             {
                 erase(pc, pc + b.size());
                 ++nFound;

src/util.cpp

@@ -283,7 +283,7 @@ int my_snprintf(char* buffer, size_t limit, const char* format, ...)
     va_start(arg_ptr, format);
     int ret = _vsnprintf(buffer, limit, format, arg_ptr);
     va_end(arg_ptr);
-    if (ret < 0 || ret >= limit)
+    if (ret < 0 || ret >= (int)limit)
     {
         ret = limit - 1;
         buffer[limit-1] = 0;