Make sure that modemRead is properly maintaining sock_available

src/TinyGsmClientA6.h

@@ -58,6 +58,10 @@ public:
     this->mux = -1;
     sock_connected = false;
 
+    // at->sockets[mux] = this;
+    //  ^^ TODO: attach the socket here at init?  Or later at connect?
+    // Currently done inconsistently between modems
+
     return true;
   }
 
@@ -71,6 +75,8 @@ public:
     if (sock_connected) {
       mux = newMux;
       at->sockets[mux] = this;
+    // ^^ TODO: attach the socet after attempting connection or above at init?
+    // Currently done inconsistently between modems
     }
     return sock_connected;
   }
@@ -112,7 +118,7 @@ public:
 
   virtual int available() {
     TINY_GSM_YIELD();
-    if (!rx.size()) {
+    if (!rx.size() && sock_connected) {
       at->maintain();
     }
     return rx.size();

src/TinyGsmClientBG96.h

@@ -62,6 +62,8 @@ public:
     got_data = false;
 
     at->sockets[mux] = this;
+    //  ^^ TODO: attach the socket here at init?  Or later at connect?
+    // Currently done inconsistently between modems
 
     return true;
   }
@@ -72,6 +74,10 @@ public:
     TINY_GSM_YIELD();
     rx.clear();
     sock_connected = at->modemConnect(host, port, mux);
+    // sock_connected = at->modemConnect(host, port, &mux);
+    // at->sockets[mux] = this;
+    // ^^ TODO: attach the socet after attempting connection or above at init?
+    // Currently done inconsistently between modems
     return sock_connected;
   }
 
@@ -97,7 +103,7 @@ public:
     rx.clear();
     at->maintain();
     while (sock_available > 0) {
-      sock_available -= at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
+      at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
       rx.clear();
       at->maintain();
     }
@@ -641,6 +647,7 @@ protected:
       return 0;
     }
     size_t len = stream.readStringUntil('\n').toInt();
+    sockets[mux]->sock_available = len;
 
     for (size_t i=0; i<len; i++) {
       while (!stream.available()) { TINY_GSM_YIELD(); }

src/TinyGsmClientESP8266.h

@@ -59,6 +59,8 @@ public:
     sock_connected = false;
 
     at->sockets[mux] = this;
+    //  ^^ TODO: attach the socket here at init?  Or later at connect?
+    // Currently done inconsistently between modems
 
     return true;
   }
@@ -69,6 +71,10 @@ public:
     TINY_GSM_YIELD();
     rx.clear();
     sock_connected = at->modemConnect(host, port, mux);
+    // sock_connected = at->modemConnect(host, port, &mux);
+    // at->sockets[mux] = this;
+    // ^^ TODO: attach the socet after attempting connection or above at init?
+    // Currently done inconsistently between modems
     return sock_connected;
   }
 
@@ -109,7 +115,7 @@ public:
 
   virtual int available() {
     TINY_GSM_YIELD();
-    if (!rx.size()) {
+    if (!rx.size() && sock_connected) {
       at->maintain();
     }
     return rx.size();
@@ -183,6 +189,10 @@ public:
     TINY_GSM_YIELD();
     rx.clear();
     sock_connected = at->modemConnect(host, port, mux, true);
+    // sock_connected = at->modemConnect(host, port, &mux);
+    // at->sockets[mux] = this;
+    // ^^ TODO: attach the socet after attempting connection or above at init?
+    // Currently done inconsistently between modems
     return sock_connected;
   }
 };

src/TinyGsmClientM590.h

@@ -59,6 +59,8 @@ public:
     sock_connected = false;
 
     at->sockets[mux] = this;
+    //  ^^ TODO: attach the socket here at init?  Or later at connect?
+    // Currently done inconsistently between modems
 
     return true;
   }
@@ -69,6 +71,10 @@ public:
     TINY_GSM_YIELD();
     rx.clear();
     sock_connected = at->modemConnect(host, port, mux);
+    // sock_connected = at->modemConnect(host, port, &mux);
+    // at->sockets[mux] = this;
+    // ^^ TODO: attach the socet after attempting connection or above at init?
+    // Currently done inconsistently between modems
     return sock_connected;
   }
 
@@ -128,7 +134,7 @@ public:
         continue;
       }
       // TODO: Read directly into user buffer?
-      if (!rx.size()) {
+      if (!rx.size() && sock_connected) {
         at->maintain();
       }
     }

src/TinyGsmClientM95.h

@@ -62,6 +62,8 @@ public:
     got_data = false;
 
     at->sockets[mux] = this;
+    //  ^^ TODO: attach the socket here at init?  Or later at connect?
+    // Currently done inconsistently between modems
 
     return true;
   }
@@ -72,6 +74,10 @@ public:
     TINY_GSM_YIELD();
     rx.clear();
     sock_connected = at->modemConnect(host, port, mux);
+    // sock_connected = at->modemConnect(host, port, &mux);
+    // at->sockets[mux] = this;
+    // ^^ TODO: attach the socet after attempting connection or above at init?
+    // Currently done inconsistently between modems
     return sock_connected;
   }
 
@@ -97,7 +103,7 @@ public:
     rx.clear();
     at->maintain();
     while (sock_available > 0) {
-      sock_available -= at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
+      at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
       rx.clear();
       at->maintain();
     }
@@ -696,6 +702,7 @@ protected:
       return 0;
     }
     size_t len = stream.readStringUntil('\n').toInt();
+    sockets[mux]->sock_available = len;
 
     for (size_t i=0; i<len; i++) {
       while (!stream.available()) { TINY_GSM_YIELD(); }

src/TinyGsmClientMC60.h

@@ -66,6 +66,8 @@ public:
     got_data = false;
 
     at->sockets[mux] = this;
+    //  ^^ TODO: attach the socket here at init?  Or later at connect?
+    // Currently done inconsistently between modems
 
     return true;
   }
@@ -76,6 +78,10 @@ public:
     TINY_GSM_YIELD();
     rx.clear();
     sock_connected = at->modemConnect(host, port, mux);
+    // sock_connected = at->modemConnect(host, port, &mux);
+    // at->sockets[mux] = this;
+    // ^^ TODO: attach the socet after attempting connection or above at init?
+    // Currently done inconsistently between modems
     return sock_connected;
   }
 
@@ -101,7 +107,7 @@ public:
     rx.clear();
     at->maintain();
     while (sock_available > 0) {
-      sock_available -= at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
+      at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
       rx.clear();
       at->maintain();
     }
@@ -724,6 +730,7 @@ protected:
       return 0;
     }
     size_t len = stream.readStringUntil('\n').toInt();
+    sockets[mux]->sock_available = len;
 
     for (size_t i=0; i<len; i++) {
       while (!stream.available()) { TINY_GSM_YIELD(); }

src/TinyGsmClientSIM7000.h

@@ -71,6 +71,8 @@ public:
     got_data = false;
 
     at->sockets[mux] = this;
+    //  ^^ TODO: attach the socket here at init?  Or later at connect?
+    // Currently done inconsistently between modems
 
     return true;
   }
@@ -81,6 +83,10 @@ public:
     TINY_GSM_YIELD();
     rx.clear();
     sock_connected = at->modemConnect(host, port, mux);
+    // sock_connected = at->modemConnect(host, port, &mux);
+    // at->sockets[mux] = this;
+    // ^^ TODO: attach the socet after attempting connection or above at init?
+    // Currently done inconsistently between modems
     return sock_connected;
   }
 
@@ -106,7 +112,7 @@ public:
     rx.clear();
     at->maintain();
     while (sock_available > 0) {
-      sock_available -= at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
+      at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
       rx.clear();
       at->maintain();
     }
@@ -228,6 +234,9 @@ public:
     TINY_GSM_YIELD();
     rx.clear();
     sock_connected = at->modemConnect(host, port, mux, true);
+    // sock_connected = at->modemConnect(host, port, &mux, true);
+    // at->sockets[mux] = this;
+    // TODO:  When is the socket attached?
     return sock_connected;
   }
 };
@@ -421,6 +430,7 @@ public:
 
   RegStatus getRegistrationStatus() {
     sendAT(GF("+CGREG?"));
+    // TODO:  Shouldn't this be CEREG for the EPS status of this 4G module?
     if (waitResponse(GF(GSM_NL "+CGREG:")) != 1) {
       return REG_UNKNOWN;
     }

src/TinyGsmClientSIM800.h

@@ -68,6 +68,8 @@ public:
     got_data = false;
 
     at->sockets[mux] = this;
+    //  ^^ TODO: attach the socket here at init?  Or later at connect?
+    // Currently done inconsistently between modems
 
     return true;
   }
@@ -78,6 +80,10 @@ public:
     TINY_GSM_YIELD();
     rx.clear();
     sock_connected = at->modemConnect(host, port, mux);
+    // sock_connected = at->modemConnect(host, port, &mux);
+    // at->sockets[mux] = this;
+    // ^^ TODO: attach the socet after attempting connection or above at init?
+    // Currently done inconsistently between modems
     return sock_connected;
   }
 
@@ -103,7 +109,7 @@ public:
     rx.clear();
     at->maintain();
     while (sock_available > 0) {
-      sock_available -= at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
+      at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
       rx.clear();
       at->maintain();
     }
@@ -223,6 +229,9 @@ public:
     TINY_GSM_YIELD();
     rx.clear();
     sock_connected = at->modemConnect(host, port, mux, true);
+    // sock_connected = at->modemConnect(host, port, &mux, true);
+    // at->sockets[mux] = this;
+    // TODO:  When is the socket attached?
     return sock_connected;
   }
 };

src/TinyGsmClientUBLOX.h

@@ -61,6 +61,11 @@ public:
     prev_check = 0;
     sock_connected = false;
     got_data = false;
+
+    // at->sockets[mux] = this;
+    //  ^^ TODO: attach the socket here at init?  Or later at connect?
+    // Currently done inconsistently between modems
+
     return true;
   }
 
@@ -81,8 +86,11 @@ public:
     }
     TINY_GSM_YIELD();
     rx.clear();
+    // sock_connected = at->modemConnect(host, port, mux);
     sock_connected = at->modemConnect(host, port, &mux);
     at->sockets[mux] = this;
+    // ^^ TODO: attach the socet after attempting connection or above at init?
+    // Currently done inconsistently between modems
     at->maintain();
     return sock_connected;
   }
@@ -109,7 +117,7 @@ public:
     rx.clear();
     at->maintain();
     while (sock_available > 0) {
-      sock_available -= at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
+      at->modemRead(TinyGsmMin((uint16_t)rx.free(), sock_available), mux);
       rx.clear();
       at->maintain();
     }
@@ -229,8 +237,10 @@ public:
     stop();
     TINY_GSM_YIELD();
     rx.clear();
+    // sock_connected = at->modemConnect(host, port, mux, true);
     sock_connected = at->modemConnect(host, port, &mux, true);
     at->sockets[mux] = this;
+    // TODO:  When is the socket attached?
     at->maintain();
     return sock_connected;
   }
@@ -809,6 +819,7 @@ protected:
     }
     streamSkipUntil(','); // Skip mux
     size_t len = stream.readStringUntil(',').toInt();
+    sockets[mux]->sock_available = len;
     streamSkipUntil('\"');
 
     for (size_t i=0; i<len; i++) {
@@ -895,7 +906,7 @@ public:
       TINY_GSM_YIELD();
       while (stream.available() > 0) {
         int a = stream.read();
-        if (a < 0) continue;
+        if (a <= 0) continue; // Skip 0x00 bytes, just in case
         data += (char)a;
         if (r1 && data.endsWith(r1)) {
           index = 1;