Simple fixes after static analyses (#1348)

source/pdo_sqlsrv/pdo_dbh.cpp

@@ -1615,7 +1615,6 @@ zend_string * pdo_sqlsrv_dbh_last_id(_Inout_ pdo_dbh_t *dbh, _In_ const zend_str
 #if PHP_VERSION_ID < 80100
             snprintf(buffer, LAST_INSERT_ID_QUERY_MAX_LEN, SEQUENCE_CURRENT_VALUE_QUERY, name);
 #else
-            const char *name_str = ZSTR_VAL(name);
             snprintf(buffer, LAST_INSERT_ID_QUERY_MAX_LEN, SEQUENCE_CURRENT_VALUE_QUERY, ZSTR_VAL(name));
 #endif
             wsql_string = utf16_string_from_mbcs_string(SQLSRV_ENCODING_CHAR, buffer, sizeof(buffer), &wsql_len);

source/shared/core_sqlsrv.h

@@ -374,6 +374,10 @@ inline void sqlsrv_free_trace( _Inout_ void* ptr, _In_ const char* file, _In_ in
 
 #else
 
+// Unlike their C standard library's counterparts the Zend Engine's memory management functions
+// emalloc or erealloc won't return NULL in case of an problem while allocating the requested 
+// memory but bail out and terminate the current request.
+// Check www.phpinternalsbook.com/php7/memory_management/zend_memory_manager.html for details
 inline void* sqlsrv_malloc( _In_ size_t size )
 {
     return emalloc( size );

source/shared/core_stmt.cpp

@@ -3673,7 +3673,7 @@ bool sqlsrv_params_container::send_next_packet(_Inout_ sqlsrv_stmt* stmt)
     }
 
     // The helper method send_stream_packet() returns false when EOF is reached
-    if (current_param->send_data_packet(stmt) == false) {
+    if (current_param && current_param->send_data_packet(stmt) == false) {
         // Now that EOF has been reached, reset current_param for next round 
         // Bear in mind that SQLParamData might request the same stream resource again
         current_param = NULL;