1 files changed, 84 insertions, 3 deletions

diff --git a/src/3rdparty/libtiff/libtiff/tif_webp.c b/src/3rdparty/libtiff/libtiff/tif_webp.c
index 07db7cc..bf9d77e 100644
--- a/src/3rdparty/libtiff/libtiff/tif_webp.c
+++ b/src/3rdparty/libtiff/libtiff/tif_webp.c
@@ -47,9 +47,11 @@ typedef struct
 {
     uint16_t nSamples; /* number of samples per pixel */
 
-    int lossless;               /* lossy/lossless compression */
-    int quality_level;          /* compression level */
-    WebPPicture sPicture;       /* WebP Picture */
+    int lossless;         /* lossy/lossless compression */
+    int lossless_exact;   /* lossless exact mode. If TRUE, R,G,B values in areas
+                             with alpha = 0 will be preserved */
+    int quality_level;    /* compression level */
+    WebPPicture sPicture; /* WebP Picture */
     WebPConfig sEncoderConfig;  /* WebP encoder config */
     uint8_t *pBuffer;           /* buffer to hold raw data on encoding */
     unsigned int buffer_offset; /* current offset into the buffer */
@@ -149,6 +151,64 @@ static int TWebPDecode(TIFF *tif, uint8_t *op, tmsize_t occ, uint16_t s)
                 segment_height = td->td_rowsperstrip;
         }
 
+        int webp_width, webp_height;
+        if (!WebPGetInfo(tif->tif_rawcp,
+                         (uint64_t)tif->tif_rawcc > UINT32_MAX
+                             ? UINT32_MAX
+                             : (uint32_t)tif->tif_rawcc,
+                         &webp_width, &webp_height))
+        {
+            TIFFErrorExtR(tif, module, "WebPGetInfo() failed");
+            return 0;
+        }
+        if ((uint32_t)webp_width != segment_width ||
+            (uint32_t)webp_height != segment_height)
+        {
+            TIFFErrorExtR(
+                tif, module, "WebP blob dimension is %dx%d. Expected %ux%u",
+                webp_width, webp_height, segment_width, segment_height);
+            return 0;
+        }
+
+#if WEBP_DECODER_ABI_VERSION >= 0x0002
+        WebPDecoderConfig config;
+        if (!WebPInitDecoderConfig(&config))
+        {
+            TIFFErrorExtR(tif, module, "WebPInitDecoderConfig() failed");
+            return 0;
+        }
+
+        const bool bWebPGetFeaturesOK =
+            WebPGetFeatures(tif->tif_rawcp,
+                            (uint64_t)tif->tif_rawcc > UINT32_MAX
+                                ? UINT32_MAX
+                                : (uint32_t)tif->tif_rawcc,
+                            &config.input) == VP8_STATUS_OK;
+
+        WebPFreeDecBuffer(&config.output);
+
+        if (!bWebPGetFeaturesOK)
+        {
+            TIFFErrorExtR(tif, module, "WebPInitDecoderConfig() failed");
+            return 0;
+        }
+
+        const int webp_bands = config.input.has_alpha ? 4 : 3;
+        if (webp_bands != sp->nSamples &&
+            /* We accept the situation where the WebP blob has only 3 bands,
+             * whereas the raster is 4 bands. This can happen when the alpha
+             * channel is fully opaque, and WebP decoding works fine in that
+             * situation.
+             */
+            !(webp_bands == 3 && sp->nSamples == 4))
+        {
+            TIFFErrorExtR(tif, module,
+                          "WebP blob band count is %d. Expected %d", webp_bands,
+                          sp->nSamples);
+            return 0;
+        }
+#endif
+
         buffer_size = segment_width * segment_height * sp->nSamples;
         if (occ == (tmsize_t)buffer_size)
         {
@@ -461,6 +521,9 @@ static int TWebPSetupEncode(TIFF *tif)
     if (sp->lossless)
     {
         sp->sPicture.use_argb = 1;
+#if WEBP_ENCODER_ABI_VERSION >= 0x0209
+        sp->sEncoderConfig.exact = sp->lossless_exact;
+#endif
     }
 #endif
 
@@ -696,6 +759,17 @@ static int TWebPVSetField(TIFF *tif, uint32_t tag, va_list ap)
                 "lossless compression.");
             return 0;
 #endif
+        case TIFFTAG_WEBP_LOSSLESS_EXACT:
+#if WEBP_ENCODER_ABI_VERSION >= 0x0209
+            sp->lossless_exact = va_arg(ap, int);
+            return 1;
+#else
+            TIFFErrorExtR(
+                tif, module,
+                "Need to upgrade WEBP driver, this version doesn't support "
+                "lossless compression.");
+            return 0;
+#endif
         default:
             return (*sp->vsetparent)(tif, tag, ap);
     }
@@ -714,6 +788,9 @@ static int TWebPVGetField(TIFF *tif, uint32_t tag, va_list ap)
         case TIFFTAG_WEBP_LOSSLESS:
             *va_arg(ap, int *) = sp->lossless;
             break;
+        case TIFFTAG_WEBP_LOSSLESS_EXACT:
+            *va_arg(ap, int *) = sp->lossless_exact;
+            break;
         default:
             return (*sp->vgetparent)(tif, tag, ap);
     }
@@ -726,6 +803,9 @@ static const TIFFField TWebPFields[] = {
     {TIFFTAG_WEBP_LOSSLESS, 0, 0, TIFF_ANY, 0, TIFF_SETGET_INT,
      TIFF_SETGET_UNDEFINED, FIELD_PSEUDO, TRUE, FALSE, "WEBP lossless/lossy",
      NULL},
+    {TIFFTAG_WEBP_LOSSLESS_EXACT, 0, 0, TIFF_ANY, 0, TIFF_SETGET_INT,
+     TIFF_SETGET_UNDEFINED, FIELD_PSEUDO, TRUE, FALSE, "WEBP exact lossless",
+     NULL},
 };
 
 int TIFFInitWebP(TIFF *tif, int scheme)
@@ -764,6 +844,7 @@ int TIFFInitWebP(TIFF *tif, int scheme)
     /* Default values for codec-specific fields */
     sp->quality_level = 75; /* default comp. level */
     sp->lossless = 0;       /* default to false */
+    sp->lossless_exact = 1; /* exact lossless mode (if lossless enabled) */
     sp->state = 0;
     sp->nSamples = 0;
     sp->psDecoder = NULL;