Cleaned up a few warnings generated by clang -Wall.

modules/juce_graphics/image_formats/pnglib/png.c

@@ -690,9 +690,8 @@ png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
 
 png_charp PNGAPI
-png_get_copyright(png_structp png_ptr)
+png_get_copyright(png_structp)
 {
-   png_ptr = png_ptr;  /* silence compiler warning about unused png_ptr */
    return ((png_charp) "\n libpng version 1.2.21 - October 4, 2007\n\
    Copyright (c) 1998-2007 Glenn Randers-Pehrson\n\
    Copyright (c) 1996-1997 Andreas Dilger\n\
@@ -708,26 +707,23 @@ png_get_copyright(png_structp png_ptr)
  * it is guaranteed that png.c uses the correct version of png.h.
  */
 png_charp PNGAPI
-png_get_libpng_ver(png_structp png_ptr)
+png_get_libpng_ver(png_structp)
 {
    /* Version of *.c files used when building libpng */
-   png_ptr = png_ptr;  /* silence compiler warning about unused png_ptr */
    return ((png_charp) PNG_LIBPNG_VER_STRING);
 }
 
 png_charp PNGAPI
-png_get_header_ver(png_structp png_ptr)
+png_get_header_ver(png_structp)
 {
    /* Version of *.h files used when building libpng */
-   png_ptr = png_ptr;  /* silence compiler warning about unused png_ptr */
    return ((png_charp) PNG_LIBPNG_VER_STRING);
 }
 
 png_charp PNGAPI
-png_get_header_version(png_structp png_ptr)
+png_get_header_version(png_structp)
 {
    /* Returns longer string containing both version and date */
-   png_ptr = png_ptr;  /* silence compiler warning about unused png_ptr */
    return ((png_charp) PNG_HEADER_VERSION_STRING
 #ifndef PNG_READ_SUPPORTED
    "     (NO READ SUPPORT)"

modules/juce_graphics/image_formats/pnglib/pngerror.c

@@ -253,7 +253,7 @@ png_default_error(png_structp, png_const_charp error_message)
    PNG_ABORT();
 #endif
 #ifdef PNG_NO_CONSOLE_IO
-   error_message = error_message; /* make compiler happy */
+   (void) error_message; /* make compiler happy */
 #endif
 }
 

modules/juce_graphics/image_formats/pnglib/pngget.c

@@ -847,20 +847,18 @@ png_get_asm_flags (png_structp png_ptr)
 
 /* this function was added to libpng 1.2.0 and should exist by default */
 png_uint_32 PNGAPI
-png_get_asm_flagmask (int flag_select)
+png_get_asm_flagmask (int)
 {
     /* obsolete, to be removed from libpng-1.4.0 */
-    flag_select=flag_select;
     return 0L;
 }
 
     /* GRR:  could add this:   && defined(PNG_MMX_CODE_SUPPORTED) */
 /* this function was added to libpng 1.2.0 */
 png_uint_32 PNGAPI
-png_get_mmx_flagmask (int flag_select, int *compilerID)
+png_get_mmx_flagmask (int, int *compilerID)
 {
     /* obsolete, to be removed from libpng-1.4.0 */
-    flag_select=flag_select;
     *compilerID = -1;   /* unknown (i.e., no asm/MMX code compiled) */
     return 0L;
 }

modules/juce_graphics/image_formats/pnglib/pngpread.c

@@ -1060,7 +1060,7 @@ 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
@@ -1156,7 +1156,7 @@ 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
@@ -1479,7 +1479,7 @@ 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 */
    }
 
 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)

modules/juce_graphics/image_formats/pnglib/pngread.c

@@ -1463,8 +1463,8 @@ 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 */

modules/juce_graphics/image_formats/pnglib/pngrutil.c

@@ -571,7 +571,7 @@ 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 */
 }
 
 #if defined(PNG_READ_gAMA_SUPPORTED)
@@ -2260,7 +2260,7 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    png_crc_finish(png_ptr, skip);
 
 #if !defined(PNG_READ_USER_CHUNKS_SUPPORTED)
-   info_ptr = info_ptr; /* quiet compiler warnings about unused info_ptr */
+   (void) info_ptr; /* quiet compiler warnings about unused info_ptr */
 #endif
 }
 

modules/juce_graphics/image_formats/pnglib/pngwrite.c

@@ -1507,8 +1507,8 @@ 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 */