diff --git a/Sources/libparsersvg/parserSVG/Base.h b/Sources/libparsersvg/parserSVG/Base.h
index c241b5e5..ac82f1f2 100644
--- a/Sources/libparsersvg/parserSVG/Base.h
+++ b/Sources/libparsersvg/parserSVG/Base.h
@@ -53,7 +53,7 @@ namespace svg
 		public:
 			Base(void) {};
 			Base(PaintState parentPaintState);
-			~Base(void) { };
+			virtual ~Base(void) { };
 			virtual bool Parse(TiXmlNode * node, agg::trans_affine& parentTrans, Vector2D<float>& sizeMax);
 			//specific drawing for AAG librairy ...
 			virtual void AggDraw(svg::Renderer& myRenderer, agg::trans_affine& basicTrans) { };
diff --git a/Sources/libpng/png/error.c b/Sources/libpng/png/error.c
index c13f9565..31f95462 100644
--- a/Sources/libpng/png/error.c
+++ b/Sources/libpng/png/error.c
@@ -354,7 +354,7 @@ png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 #else
    warning_message = warning_message; /* Make compiler happy */
 #endif
-   png_ptr = png_ptr; /* Make compiler happy */
+   (void)png_ptr; /* Make compiler happy */
 }
 #endif /* PNG_WARNINGS_SUPPORTED */
 
diff --git a/Sources/libpng/png/png.c b/Sources/libpng/png/png.c
index 98f813ca..ab121a29 100644
--- a/Sources/libpng/png/png.c
+++ b/Sources/libpng/png/png.c
@@ -545,7 +545,7 @@ png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
 png_charp PNGAPI
 png_get_copyright(png_structp png_ptr)
 {
-   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
+   (void)png_ptr;  /* Silence compiler warning about unused png_ptr */
 #ifdef PNG_STRING_COPYRIGHT
       return PNG_STRING_COPYRIGHT
 #else
@@ -577,7 +577,7 @@ png_charp PNGAPI
 png_get_libpng_ver(png_structp png_ptr)
 {
    /* Version of *.c files used when building libpng */
-   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
+   (void)png_ptr;  /* Silence compiler warning about unused png_ptr */
    return ((png_charp) PNG_LIBPNG_VER_STRING);
 }
 
@@ -585,7 +585,7 @@ png_charp PNGAPI
 png_get_header_ver(png_structp png_ptr)
 {
    /* Version of *.h files used when building libpng */
-   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
+   (void)png_ptr;  /* Silence compiler warning about unused png_ptr */
    return ((png_charp) PNG_LIBPNG_VER_STRING);
 }
 
@@ -593,7 +593,7 @@ png_charp PNGAPI
 png_get_header_version(png_structp png_ptr)
 {
    /* Returns longer string containing both version and date */
-   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
+   (void)png_ptr;  /* Silence compiler warning about unused png_ptr */
 #ifdef __STDC__
    return ((png_charp) PNG_HEADER_VERSION_STRING
 #ifndef PNG_READ_SUPPORTED
diff --git a/Sources/libpng/png/pread.c b/Sources/libpng/png/pread.c
index 045f7d88..2b1ccda0 100644
--- a/Sources/libpng/png/pread.c
+++ b/Sources/libpng/png/pread.c
@@ -1164,7 +1164,7 @@ png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
    if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
       {
          png_error(png_ptr, "Out of place tEXt");
-         info_ptr = info_ptr; /* To quiet some compiler warnings */
+         (void)info_ptr; /* To quiet some compiler warnings */
       }
 
 #ifdef PNG_MAX_MALLOC_64K
@@ -1262,7 +1262,7 @@ png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
    if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
       {
          png_error(png_ptr, "Out of place zTXt");
-         info_ptr = info_ptr; /* To quiet some compiler warnings */
+         (void)info_ptr; /* To quiet some compiler warnings */
       }
 
 #ifdef PNG_MAX_MALLOC_64K
@@ -1463,7 +1463,7 @@ png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
    if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
       {
          png_error(png_ptr, "Out of place iTXt");
-         info_ptr = info_ptr; /* To quiet some compiler warnings */
+         (void)info_ptr; /* To quiet some compiler warnings */
       }
 
 #ifdef PNG_MAX_MALLOC_64K
@@ -1598,7 +1598,7 @@ png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
 #endif
          png_chunk_error(png_ptr, "unknown critical chunk");
 
-      info_ptr = info_ptr; /* To quiet some compiler warnings */
+      (void)info_ptr; /* To quiet some compiler warnings */
    }
 
 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
diff --git a/Sources/libpng/png/read.c b/Sources/libpng/png/read.c
index fc10ad22..35ad2c3a 100644
--- a/Sources/libpng/png/read.c
+++ b/Sources/libpng/png/read.c
@@ -1352,8 +1352,8 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
    /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
    png_read_end(png_ptr, info_ptr);
 
-   transforms = transforms; /* Quiet compiler warnings */
-   params = params;
+   (void)transforms; /* Quiet compiler warnings */
+   (void)params;
 
 }
 #endif /* PNG_INFO_IMAGE_SUPPORTED */
diff --git a/Sources/libpng/png/rutil.c b/Sources/libpng/png/rutil.c
index 13f4707d..ce4daec7 100644
--- a/Sources/libpng/png/rutil.c
+++ b/Sources/libpng/png/rutil.c
@@ -638,7 +638,7 @@ png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
    png_crc_finish(png_ptr, length);
 
-   info_ptr = info_ptr; /* Quiet compiler warnings about unused info_ptr */
+   (void)info_ptr; /* Quiet compiler warnings about unused info_ptr */
 }
 
 #ifdef PNG_READ_gAMA_SUPPORTED
diff --git a/Sources/libpng/png/write.c b/Sources/libpng/png/write.c
index 13e38f9a..120a1ca4 100644
--- a/Sources/libpng/png/write.c
+++ b/Sources/libpng/png/write.c
@@ -1450,8 +1450,8 @@ png_write_png(png_structp png_ptr, png_infop info_ptr,
    /* It is REQUIRED to call this to finish writing the rest of the file */
    png_write_end(png_ptr, info_ptr);
 
-   transforms = transforms; /* Quiet compiler warnings */
-   params = params;
+   (void)transforms; /* Quiet compiler warnings */
+   (void)params;
 }
 #endif
 #endif /* PNG_WRITE_SUPPORTED */