Fix a pair of warnings in stb_image.h

stb_image.h

@@ -53,7 +53,7 @@ RECENT REVISION HISTORY:
       2.12  (2016-04-02) fix typo in 2.11 PSD fix that caused crashes
       2.11  (2016-04-02) 16-bit PNGS; enable SSE2 in non-gcc x64
                          RGB-format JPEG; remove white matting in PSD;
-                         allocate large structures on the stack; 
+                         allocate large structures on the stack;
                          correct channel count for PNG & BMP
       2.10  (2016-01-22) avoid warning introduced in 2.09
       2.09  (2016-01-16) 16-bit TGA; comments in PNM files; STBI_REALLOC_SIZED
@@ -96,7 +96,7 @@ RECENT REVISION HISTORY:
     Ryamond Barbiero        Paul Du Bois       Engin Manap        github:snagar
     Michaelangel007@github  Oriol Ferrer Mesia Dale Weiler        github:Zelex
     Philipp Wiesemann       Josh Tobin         github:rlyeh       github:grim210@github
-    Blazej Dariusz Roszkowski                  github:sammyhw
+    Blazej Dariusz Roszkowski                  github:sammyhw     GrayHatter@uTox
 
 */
 
@@ -267,11 +267,11 @@ RECENT REVISION HISTORY:
 // ===========================================================================
 //
 // ADDITIONAL CONFIGURATION
-// 
+//
 //  - You can suppress implementation of any of the decoders to reduce
 //    your code footprint by #defining one or more of the following
 //    symbols before creating the implementation.
-// 
+//
 //        STBI_NO_JPEG
 //        STBI_NO_PNG
 //        STBI_NO_BMP
@@ -281,11 +281,11 @@ RECENT REVISION HISTORY:
 //        STBI_NO_HDR
 //        STBI_NO_PIC
 //        STBI_NO_PNM   (.ppm and .pgm)
-// 
+//
 //  - You can request *only* certain decoders and suppress all other ones
 //    (this will be more forward-compatible, as addition of new decoders
 //    doesn't require you to disable them explicitly):
-// 
+//
 //        STBI_ONLY_JPEG
 //        STBI_ONLY_PNG
 //        STBI_ONLY_BMP
@@ -295,7 +295,7 @@ RECENT REVISION HISTORY:
 //        STBI_ONLY_HDR
 //        STBI_ONLY_PIC
 //        STBI_ONLY_PNM   (.ppm and .pgm)
-// 
+//
 //   - If you use STBI_NO_PNG (or _ONLY_ without PNG), and you still
 //     want the zlib decoder to be available, #define STBI_SUPPORT_ZLIB
 //
@@ -1761,7 +1761,7 @@ static void stbi__build_fast_ac(stbi__int16 *fast_ac, stbi__huffman *h)
             // magnitude code followed by receive_extend code
             int k = ((i << len) & ((1 << FAST_BITS) - 1)) >> (FAST_BITS - magbits);
             int m = 1 << (magbits - 1);
-            if (k < m) k += (-1 << magbits) + 1;
+            if (k < m) k += (~0U << magbits) + 1;
             // if the result is small enough, we can fit it in fast_ac table
             if (k >= -128 && k <= 127)
                fast_ac[i] = (stbi__int16) ((k << 8) + (run << 4) + (len + magbits));
@@ -3594,6 +3594,7 @@ static stbi_uc *load_jpeg_image(stbi__jpeg *z, int *out_x, int *out_y, int *comp
 
 static void *stbi__jpeg_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri)
 {
+   (void)ri; // This unused warning is safe to ignore.
    unsigned char* result;
    stbi__jpeg* j = (stbi__jpeg*) stbi__malloc(sizeof(stbi__jpeg));
    j->s = s;
@@ -4605,7 +4606,7 @@ static int stbi__parse_png_file(stbi__png *z, int scan, int req_comp)
             s->img_y = stbi__get32be(s); if (s->img_y > (1 << 24)) return stbi__err("too large","Very large image (corrupt?)");
             z->depth = stbi__get8(s);  if (z->depth != 1 && z->depth != 2 && z->depth != 4 && z->depth != 8 && z->depth != 16)  return stbi__err("1/2/4/8/16-bit only","PNG not supported: 1/2/4/8/16-bit only");
             color = stbi__get8(s);  if (color > 6)         return stbi__err("bad ctype","Corrupt PNG");
-			if (color == 3 && z->depth == 16)                  return stbi__err("bad ctype","Corrupt PNG");
+            if (color == 3 && z->depth == 16)                  return stbi__err("bad ctype","Corrupt PNG");
             if (color == 3) pal_img_n = 3; else if (color & 1) return stbi__err("bad ctype","Corrupt PNG");
             comp  = stbi__get8(s);  if (comp) return stbi__err("bad comp method","Corrupt PNG");
             filter= stbi__get8(s);  if (filter) return stbi__err("bad filter method","Corrupt PNG");
@@ -4888,7 +4889,7 @@ static void *stbi__bmp_parse_header(stbi__context *s, stbi__bmp_data *info)
    info->offset = stbi__get32le(s);
    info->hsz = hsz = stbi__get32le(s);
    info->mr = info->mg = info->mb = info->ma = 0;
-   
+
    if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108 && hsz != 124) return stbi__errpuc("unknown BMP", "BMP type not supported: unknown");
    if (hsz == 12) {
       s->img_x = stbi__get16le(s);
@@ -4973,7 +4974,7 @@ static void *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req
    stbi__bmp_data info;
    STBI_NOTUSED(ri);
 
-   info.all_a = 255;   
+   info.all_a = 255;
    if (stbi__bmp_parse_header(s, &info) == NULL)
       return NULL; // error code already set
 
@@ -5092,7 +5093,7 @@ static void *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req
          stbi__skip(s, pad);
       }
    }
-   
+
    // if alpha channel is all 0s, replace with all 255s
    if (target == 4 && all_a == 0)
       for (i=4*s->img_x*s->img_y-1; i >= 0; i -= 4)
@@ -6537,7 +6538,7 @@ static int stbi__bmp_info(stbi__context *s, int *x, int *y, int *comp)
    void *p;
    stbi__bmp_data info;
 
-   info.all_a = 255;   
+   info.all_a = 255;
    p = stbi__bmp_parse_header(s, &info);
    stbi__rewind( s );
    if (p == NULL)
@@ -7012,38 +7013,38 @@ This software is available under 2 licenses -- choose whichever you prefer.
 ------------------------------------------------------------------------------
 ALTERNATIVE A - MIT License
 Copyright (c) 2017 Sean Barrett
-Permission is hereby granted, free of charge, to any person obtaining a copy of 
+Permission is hereby granted, free of charge, to any person obtaining a copy of
-this software and associated documentation files (the "Software"), to deal in 
+this software and associated documentation files (the "Software"), to deal in
-the Software without restriction, including without limitation the rights to 
+the Software without restriction, including without limitation the rights to
-use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-of the Software, and to permit persons to whom the Software is furnished to do 
+of the Software, and to permit persons to whom the Software is furnished to do
 so, subject to the following conditions:
-The above copyright notice and this permission notice shall be included in all 
+The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 ------------------------------------------------------------------------------
 ALTERNATIVE B - Public Domain (www.unlicense.org)
 This is free and unencumbered software released into the public domain.
-Anyone is free to copy, modify, publish, use, compile, sell, or distribute this 
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
-software, either in source code form or as a compiled binary, for any purpose, 
+software, either in source code form or as a compiled binary, for any purpose,
 commercial or non-commercial, and by any means.
-In jurisdictions that recognize copyright laws, the author or authors of this 
+In jurisdictions that recognize copyright laws, the author or authors of this
-software dedicate any and all copyright interest in the software to the public 
+software dedicate any and all copyright interest in the software to the public
-domain. We make this dedication for the benefit of the public at large and to 
+domain. We make this dedication for the benefit of the public at large and to
-the detriment of our heirs and successors. We intend this dedication to be an 
+the detriment of our heirs and successors. We intend this dedication to be an
-overt act of relinquishment in perpetuity of all present and future rights to 
+overt act of relinquishment in perpetuity of all present and future rights to
 this software under copyright law.
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 
+AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
-ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 ------------------------------------------------------------------------------
 */