Fix 'Wconversion' warns: casting ints and check tcp endpoints

src/groups/mwc/mwcio/mwcio_channel.cpp

@@ -63,7 +63,7 @@ bool ChannelWatermarkType::fromAscii(ChannelWatermarkType::Enum* out,
 #define CHECKVALUE(M)                                                         \
     if (bdlb::String::areEqualCaseless(toAscii(ChannelWatermarkType::e_##M),  \
                                        str.data(),                            \
-                                       str.length())) {                       \
+                                       static_cast<int>(str.length()))) {     \
         *out = ChannelWatermarkType::e_##M;                                   \
         return true;                                                          \
     }

src/groups/mwc/mwcio/mwcio_tcpendpoint.cpp

@@ -90,11 +90,13 @@ bool TCPEndpoint::fromUri(const bsl::string& uri)
     }
 
     // Extract the port part: i.e. after the last ':'
-    d_port = bsl::strtol(uri.c_str() + colon + 1, 0, 10);
+    const long port = bsl::strtol(uri.c_str() + colon + 1, 0, 10);
 
-    if (d_port == 0) {
+    // For simplicity, do not accept ambiguous `port` value 0
+    if (port <= 0 || port > 65535) {
         return false;  // RETURN
     }
+    d_port = static_cast<int>(port);
 
     // Extract the host part: i.e. between '/' and ':'
     d_host.assign(uri, k_SCHEME_LEN, colon - k_SCHEME_LEN);
@@ -111,7 +113,18 @@ void TCPEndpoint::fromUriRaw(const bsl::string& uri)
 
     const size_t separator = uri.find_last_of(':');
 
-    d_port = bsl::strtol(uri.c_str() + separator + 1, 0, 10);
+    if (separator == bsl::string::npos) {
+        return;  // RETURN
+    }
+
+    const long port = bsl::strtol(uri.c_str() + separator + 1, 0, 10);
+
+    // For simplicity, do not accept ambiguous `port` value 0
+    if (port <= 0 || port > 65535) {
+        return;  // RETURN
+    }
+
+    d_port = static_cast<int>(port);
     d_host.assign(uri, k_SCHEME_LEN, separator - k_SCHEME_LEN);
 }