From e35ebf137d8ee0d5c7949e9c888db0e8e25d0a1c Mon Sep 17 00:00:00 2001
From: Me No Dev <me-no-dev@users.noreply.github.com>
Date: Fri, 15 Jul 2016 10:15:44 +0300
Subject: [PATCH] Add support to Print::printf for printing from flash (#2266)

* Add support to Print::printf for printing from flash
---
 cores/esp8266/Print.cpp | 23 +++++++++++++++++++++++
 cores/esp8266/Print.h   |  1 +
 2 files changed, 24 insertions(+)

diff --git a/cores/esp8266/Print.cpp b/cores/esp8266/Print.cpp
index 5b481fd40..0c3d362ab 100644
--- a/cores/esp8266/Print.cpp
+++ b/cores/esp8266/Print.cpp
@@ -63,6 +63,29 @@ size_t Print::printf(const char *format, ...) {
     return len;
 }
 
+size_t Print::printf_P(PGM_P format, ...) {
+    va_list arg;
+    va_start(arg, format);
+    char temp[64];
+    char* buffer = temp;
+    size_t len = vsnprintf_P(temp, sizeof(temp), format, arg);
+    va_end(arg);
+    if (len > sizeof(temp) - 1) {
+        buffer = new char[len + 1];
+        if (!buffer) {
+            return 0;
+        }
+        va_start(arg, format);
+        vsnprintf_P(buffer, len + 1, format, arg);
+        va_end(arg);
+    }
+    len = write((const uint8_t*) buffer, len);
+    if (buffer != temp) {
+        delete[] buffer;
+    }
+    return len;
+}
+
 size_t Print::print(const __FlashStringHelper *ifsh) {
     PGM_P p = reinterpret_cast<PGM_P>(ifsh);
 
diff --git a/cores/esp8266/Print.h b/cores/esp8266/Print.h
index a0df267c1..69f5ad621 100644
--- a/cores/esp8266/Print.h
+++ b/cores/esp8266/Print.h
@@ -64,6 +64,7 @@ class Print {
         }
 
         size_t printf(const char * format, ...)  __attribute__ ((format (printf, 2, 3)));
+        size_t printf_P(PGM_P format, ...) __attribute__((format(printf, 2, 3)));
         size_t print(const __FlashStringHelper *);
         size_t print(const String &);
         size_t print(const char[]);