From 5c7d71e6af567726195a2145e7ea026adf736ba2 Mon Sep 17 00:00:00 2001
From: chrismapp <42716253+chrismapp@users.noreply.github.com>
Date: Tue, 13 May 2025 19:39:16 +0100
Subject: [PATCH] fix(bin_decoder): fix build warnings when decompressing LZ4
 compressed images (#8234)

Co-authored-by: Liam Howatt <30486941+liamHowatt@users.noreply.github.com>
---
 src/libs/bin_decoder/lv_bin_decoder.c | 66 ++++++++++++++++-----------
 1 file changed, 39 insertions(+), 27 deletions(-)

diff --git a/src/libs/bin_decoder/lv_bin_decoder.c b/src/libs/bin_decoder/lv_bin_decoder.c
index 368fcc6036..afda36b526 100644
--- a/src/libs/bin_decoder/lv_bin_decoder.c
+++ b/src/libs/bin_decoder/lv_bin_decoder.c
@@ -1098,6 +1098,26 @@ static lv_fs_res_t fs_read_file_at(lv_fs_file_t * f, uint32_t pos, void * buff,
 
 static lv_result_t decompress_image(lv_image_decoder_dsc_t * dsc, const lv_image_compressed_t * compressed)
 {
+    /* At least one compression method must be enabled */
+#if (LV_USE_LZ4 || LV_USE_RLE)
+    /* Check if the decompression method is enabled and valid */
+    if(compressed->method == LV_IMAGE_COMPRESS_RLE) {
+#if !LV_USE_RLE
+        LV_LOG_WARN("RLE decompression is not enabled");
+        return LV_RESULT_INVALID;
+#endif
+    }
+    else if(compressed->method == LV_IMAGE_COMPRESS_LZ4) {
+#if !LV_USE_LZ4
+        LV_LOG_WARN("LZ4 decompression is not enabled");
+        return LV_RESULT_INVALID;
+#endif
+    }
+    else {
+        LV_LOG_WARN("Unknown compression method: %" LV_PRIu32, compressed->method);
+        return LV_RESULT_INVALID;
+    }
+
     /*Need to store decompressed data to decoder to free on close*/
     decoder_data_t * decoder_data = get_decoder_data(dsc);
     if(decoder_data == NULL) {
@@ -1107,8 +1127,7 @@ static lv_result_t decompress_image(lv_image_decoder_dsc_t * dsc, const lv_image
     uint8_t * img_data;
     uint32_t out_len = compressed->decompressed_size;
     uint32_t input_len = compressed->compressed_size;
-    LV_UNUSED(input_len);
-    LV_UNUSED(out_len);
+    uint32_t len = 0;
 
     lv_draw_buf_t * decompressed = lv_draw_buf_create_ex(image_cache_draw_buf_handlers, dsc->header.w, dsc->header.h,
                                                          dsc->header.cf,
@@ -1134,45 +1153,38 @@ static lv_result_t decompress_image(lv_image_decoder_dsc_t * dsc, const lv_image
             pixel_byte = 2;
         else
             pixel_byte = (lv_color_format_get_bpp(dsc->header.cf) + 7) >> 3;
+
         const uint8_t * input = compressed->data;
         uint8_t * output = img_data;
-        uint32_t len;
+
         len = lv_rle_decompress(input, input_len, output, out_len, pixel_byte);
-        if(len != compressed->decompressed_size) {
-            LV_LOG_WARN("Decompress failed: %" LV_PRIu32 ", got: %" LV_PRIu32, out_len, len);
-            lv_draw_buf_destroy(decompressed);
-            return LV_RESULT_INVALID;
-        }
-#else
-        LV_LOG_WARN("RLE decompress is not enabled");
-        lv_draw_buf_destroy(decompressed);
-        return LV_RESULT_INVALID;
-#endif
+#endif /* LV_USE_RLE */
     }
     else if(compressed->method == LV_IMAGE_COMPRESS_LZ4) {
 #if LV_USE_LZ4
         const char * input = (const char *)compressed->data;
         char * output = (char *)img_data;
-        int len;
-        len = LZ4_decompress_safe(input, output, input_len, out_len);
-        if(len < 0 || (uint32_t)len != compressed->decompressed_size) {
-            LV_LOG_WARN("Decompress failed: %" LV_PRId32 ", got: %" LV_PRId32, out_len, len);
-            lv_draw_buf_destroy(decompressed);
-            return LV_RESULT_INVALID;
+
+        int ret = LZ4_decompress_safe(input, output, (int)input_len, (int)out_len);
+        if(ret >= 0) {
+            /* Cast is safe because of the above check */
+            len = (uint32_t)ret;
         }
-#else
-        LV_LOG_WARN("LZ4 decompress is not enabled");
-        lv_draw_buf_destroy(decompressed);
-        return LV_RESULT_INVALID;
-#endif
+#endif /* LV_USE_LZ4 */
     }
-    else {
-        LV_UNUSED(img_data);
-        LV_LOG_WARN("Unknown compression method: %d", compressed->method);
+
+    if(len != compressed->decompressed_size) {
+        LV_LOG_WARN("Decompress failed: %" LV_PRIu32 ", got: %" LV_PRIu32, out_len, len);
         lv_draw_buf_destroy(decompressed);
         return LV_RESULT_INVALID;
     }
 
     decoder_data->decompressed = decompressed; /*Free on decoder close*/
     return LV_RESULT_OK;
+#else
+    LV_UNUSED(dsc);
+    LV_UNUSED(compressed);
+    LV_LOG_WARN("At least one compression method must be enabled");
+    return LV_RESULT_INVALID;
+#endif /* (LV_USE_LZ4 || LV_USE_RLE) */
 }