Fix AT_CellularSMS::list_messages breaking in text mode when CRLF is contained in SMS payload text

Author: davidalo

connectivity/cellular/include/cellular/framework/API/ATHandler.h

@@ -318,6 +318,13 @@ class ATHandler {
      */
     void skip_param(ssize_t len, uint32_t count);
 
+    /** Consumes the given length from the reading buffer even if the stop tag has been found
+     *
+     *  @param len length to be consumed from reading buffer
+     *  @param count number of parameters to be skipped
+     */
+    void skip_param_bytes(ssize_t len, uint32_t count);
+
     /** Reads given number of bytes from receiving buffer without checking any subparameter delimiters, such as comma.
      *
      *  @param buf output buffer for the read
@@ -408,6 +415,12 @@ class ATHandler {
      */
     bool consume_to_stop_tag();
 
+    /**  Consumes the received content until current stop tag is found even if stop tag has been found previously
+     *
+     *  @return true if stop tag is found, false otherwise
+     */
+    bool consume_to_stop_tag_even_found();
+
     /** Return the last 3GPP error code.
      *  @return last 3GPP error code
      */

connectivity/cellular/source/framework/AT/AT_CellularSMS.cpp

@@ -1058,8 +1058,18 @@ nsapi_error_t AT_CellularSMS::list_messages()
             // +CMGL: <index>,<stat>,<oa/da>,[<alpha>],[<scts>][,<tooa/toda>,<length>]<CR><LF><data>[<CR><LF>
             // +CMGL: <index>,<stat>,<da/oa>,[<alpha>],[<scts>][,<tooa/toda>,<length>]<CR><LF><data>[...]]
             index = _at.read_int();
-            (void)_at.consume_to_stop_tag(); // consume until <CR><LF>
-            (void)_at.consume_to_stop_tag(); // consume until <CR><LF>
+            _at.read_string(buffer, SMS_STATUS_SIZE);
+            _at.read_string(buffer, SMS_MAX_PHONE_NUMBER_SIZE);
+            _at.skip_param(); // <alpha>
+            _at.read_string(buffer, SMS_MAX_TIME_STAMP_SIZE);
+            _at.read_int();
+            int size = _at.read_int(); // length
+            _at.consume_to_stop_tag(); //  consume until <CR><LF> end of header
+            if (size > 0) {
+                // we can not use skip param because we already consumed stop tag
+                _at.skip_param_bytes(size, 1);
+            }
+            _at.consume_to_stop_tag_even_found(); // consume until <CR><LF> -> data
         }
 
         if (index >= 0) {

connectivity/cellular/source/framework/device/ATHandler.cpp

@@ -484,6 +484,26 @@ void ATHandler::skip_param(ssize_t len, uint32_t count)
     return;
 }
 
+void ATHandler::skip_param_bytes(ssize_t len, uint32_t count)
+{
+    if (!ok_to_proceed()) {
+        return;
+    }
+
+    for (uint32_t i = 0; i < count; i++) {
+        ssize_t read_len = 0;
+        while (read_len < len) {
+            int c = get_char();
+            if (c == -1) {
+                set_error(NSAPI_ERROR_DEVICE_ERROR);
+                return;
+            }
+            read_len++;
+        }
+    }
+    return;
+}
+
 ssize_t ATHandler::read_bytes(uint8_t *buf, size_t len)
 {
     if (!ok_to_proceed()) {
@@ -1093,6 +1113,26 @@ bool ATHandler::consume_to_stop_tag()
     return false;
 }
 
+
+bool ATHandler::consume_to_stop_tag_even_found()
+{
+    if (_error_found) {
+        return true;
+    }
+
+    if (!_is_fh_usable) {
+        _last_err = NSAPI_ERROR_BUSY;
+        return true;
+    }
+
+    if (consume_to_tag((const char *)_stop_tag->tag, true)) {
+        return true;
+    }
+
+    clear_error();
+    return false;
+}
+
 // consume by size needed?
 
 void ATHandler::resp_stop()