Merge pull request #350 from bobwolff68/master

PaintYourDragon · web-flow · commit 05dda5d5fb28 · 2021-09-06T20:52:14.000-07:00
Dangerous edge case for non-null-terminated string
diff --git a/Adafruit_GFX.cpp b/Adafruit_GFX.cpp
@@ -1661,6 +1661,7 @@ void Adafruit_GFX_Button::initButtonUL(Adafruit_GFX *gfx, int16_t x1,
   _textsize_y = textsize_y;
   _gfx = gfx;
   strncpy(_label, label, 9);
+  _label[9] = 0;  // strncpy does not place a null at the end. When 'label' is 9 characters, _label is not terminated.
 }
 
 /**************************************************************************/

Original file line number	Diff line number	Diff line change
`@@ -1661,6 +1661,7 @@ void Adafruit_GFX_Button::initButtonUL(Adafruit_GFX *gfx, int16_t x1,`
`1661`	`1661`	`_textsize_y = textsize_y;`
`1662`	`1662`	`_gfx = gfx;`
`1663`	`1663`	`strncpy(_label, label, 9);`
	`1664`	`+ _label[9] = 0; // strncpy does not place a null at the end. When 'label' is 9 characters, _label is not terminated.`
`1664`	`1665`	`}`
`1665`	`1666`
`1666`	`1667`	`/**************************************************************************/`