Fix Coverity scan issues and add false-positive annotations

Source/core/ProcessInfo.cpp

@@ -145,7 +145,7 @@ namespace Core {
                     int fd;
 
                     snprintf(buffer, sizeof(buffer), "/proc/%d/stat", pid);
-                    if ((fd = open(buffer, O_RDONLY)) > 0) {
+                    if ((fd = open(buffer, O_RDONLY)) != -1) {
                         if (read(fd, buffer, sizeof(buffer) - sizeof(buffer[0])) > 0) {
                             int ppid = 0;
                             sscanf(buffer, "%*d (%*[^)]) %*c %d", &ppid);
@@ -423,7 +423,7 @@ namespace Core {
         int VmSize = 0;
 
         snprintf(buffer, sizeof(buffer), "/proc/%d/statm", _pid);
-        if ((fd = open(buffer, O_RDONLY)) > 0) {
+        if ((fd = open(buffer, O_RDONLY)) != -1) {
             ssize_t readAmount = 0;
             if ((readAmount = read(fd, buffer, sizeof(buffer))) > 0) {
                 ssize_t nulIndex = std::min(readAmount, static_cast<ssize_t>(sizeof(buffer) - 1));
@@ -454,7 +454,7 @@ namespace Core {
         int VmRSS = 0;
 
         snprintf(buffer, sizeof(buffer), "/proc/%d/statm", _pid);
-        if ((fd = open(buffer, O_RDONLY)) > 0) {
+        if ((fd = open(buffer, O_RDONLY)) != -1) {
             ssize_t readAmount = 0;
             if ((readAmount = read(fd, buffer, sizeof(buffer))) > 0) {
                 ssize_t nulIndex = std::min(readAmount, static_cast<ssize_t>(sizeof(buffer) - 1));
@@ -485,7 +485,7 @@ namespace Core {
         int Share = 0;
 
         snprintf(buffer, sizeof(buffer), "/proc/%d/statm", _pid);
-        if ((fd = open(buffer, O_RDONLY)) > 0) {
+        if ((fd = open(buffer, O_RDONLY)) != -1) {
             ssize_t readAmount = 0;
             if ((readAmount = read(fd, buffer, sizeof(buffer))) > 0) {
                 ssize_t nulIndex = std::min(readAmount, static_cast<ssize_t>(sizeof(buffer) - 1));

Source/core/ResourceMonitor.h

@@ -209,8 +209,8 @@ namespace Core {
                 char procfn[64];
                 snprintf(procfn, sizeof(procfn), "/proc/self/fd/%d", info.descriptor);
 
-                size_t len = readlink(procfn, info.filename, sizeof(info.filename) - 1);
-                info.filename[len] = '\0';
+                ssize_t len = readlink(procfn, info.filename, sizeof(info.filename) - 1);
+                info.filename[len >= 0 ? len : 0] = '\0';
                 #endif
                 #ifdef __WINDOWS__
                 info.monitor = 0;

Source/core/SerialPort.cpp

@@ -848,6 +848,9 @@ void SerialPort::Read(const uint16_t readBytes)
                 if (_sendOffset < _sendBytes) {
                     uint32_t sendSize;
 
+                    // coverity[overflow_sink] - False positive: _sendBytes and _sendOffset are uint16_t (max 65535),
+                    // SendData() returns uint16_t, and POSIX guarantees write() returns at most count bytes.
+                    // The guard above ensures _sendBytes > _sendOffset, so neither subtraction nor addition can overflow.
                     sendSize = write(_descriptor, reinterpret_cast<const char*>(&_sendBuffer[_sendOffset]),
                         _sendBytes - _sendOffset);
 
@@ -888,6 +891,9 @@ void SerialPort::Read(const uint16_t readBytes)
                 uint32_t size = ::read(_descriptor, reinterpret_cast<char*>(&_receiveBuffer[_readBytes]), _receiveBufferSize - _readBytes);
 
                 if ((size != static_cast<uint32_t>(~0)) && (size != 0)) {
+                    // coverity[INTEGER_OVERFLOW] - Intentional: POSIX read() returns at most the requested count
+                    // (_receiveBufferSize - _readBytes), which is a uint16_t difference and thus <= UINT16_MAX.
+                    // The sum _readBytes + size therefore never exceeds _receiveBufferSize, so no overflow occurs.
                     _readBytes += size;
 
                     if (_readBytes != 0) {

Source/core/SocketPort.cpp

@@ -880,7 +880,7 @@ namespace Thunder {
             // See if we need to bind to a specific interface.
             if ((l_Result != INVALID_SOCKET) && (specificInterface.empty() == false)) {
 
-                struct ifreq interface;
+                struct ifreq interface = {};
 #ifdef __APPLE__
                 strncpy(interface.ifr_name, specificInterface.c_str(), IFNAMSIZ - 1);
                 int index = if_nametoindex(interface.ifr_name);

Source/core/SystemInfo.cpp

@@ -262,6 +262,8 @@ namespace Core {
             uint64_t CurrentIdleTime = CpuFields[3]; // 3 is index of idle ticks time
             uint64_t CurrentTickCount = 0L;
 
+            // coverity[OVERRUN] - Intentional: fscanf fills at most 4 fields (matching the 4 format specifiers),
+            // so numFields <= 4 and i < numFields always clamps the loop within CpuFields[0..3].
             for (int i = 0; i < numFields && i < 10; ++i) {
                 CurrentTickCount += CpuFields[i];
             }

Source/cryptalgo/HMAC.h

@@ -70,7 +70,10 @@ namespace Crypto {
             }
 
             // We have a suitable key, move it to the inner and outer pads
+            // coverity[overrun] - False positive (#754): keyLength is always <= sizeof(_innerKeyPad) (64);
+            //                     when keyLength == 64 the memset count is 0, so no bytes are written.
             ::memset(&_innerKeyPad[keyLength], 0x36, sizeof(_innerKeyPad) - keyLength);
+            // coverity[overrun] - False positive (#770): same reasoning as above for _outerKeyPad.
             ::memset(&_outerKeyPad[keyLength], 0x5C, sizeof(_outerKeyPad) - keyLength);
 
             /* XOR key with inner keypad and outer key pad values */