diff --git a/arm/arm_init.c b/arm/arm_init.c
index ab22525b3..3a89998ab 100644
--- a/arm/arm_init.c
+++ b/arm/arm_init.c
@@ -31,23 +31,21 @@
  * has partial support is contrib/arm-neon/linux.c - a generic Linux
  * implementation which reads /proc/cpufino.
  */
-#include <signal.h> /* for sig_atomic_t */
-
 #ifndef PNG_ARM_NEON_FILE
-#  if defined(__aarch64__) || defined(_M_ARM64)
-     /* ARM Neon is expected to be unconditionally available on ARM64. */
-#    error "PNG_ARM_NEON_CHECK_SUPPORTED must not be defined on this platform"
-#  elif defined(__linux__)
-#    define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
-#  else
-#    error "No support for run-time ARM Neon checking; use compile-time options"
+#  ifdef __linux__
+#     define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
 #  endif
 #endif
 
-static int png_have_neon(png_structp png_ptr);
 #ifdef PNG_ARM_NEON_FILE
-#  include PNG_ARM_NEON_FILE
-#endif
+
+#include <signal.h> /* for sig_atomic_t */
+static int png_have_neon(png_structp png_ptr);
+#include PNG_ARM_NEON_FILE
+
+#else  /* PNG_ARM_NEON_FILE */
+#  error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks"
+#endif /* PNG_ARM_NEON_FILE */
 #endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
 
 #ifndef PNG_ALIGNED_MEMORY_SUPPORTED
diff --git a/arm/palette_neon_intrinsics.c b/arm/palette_neon_intrinsics.c
index 92c7d6f9f..49909d475 100644
--- a/arm/palette_neon_intrinsics.c
+++ b/arm/palette_neon_intrinsics.c
@@ -65,12 +65,11 @@ png_do_expand_palette_rgba8_neon(png_structrp png_ptr, png_row_infop row_info,
    png_uint_32 row_width = row_info->width;
    const png_uint_32 *riffled_palette =
       (const png_uint_32 *)png_ptr->riffled_palette;
-   const png_uint_32 pixels_per_chunk = 4;
-   png_uint_32 i;
+   const png_int_32 pixels_per_chunk = 4;
+   int i;
 
    png_debug(1, "in png_do_expand_palette_rgba8_neon");
 
-   PNG_UNUSED(row)
    if (row_width < pixels_per_chunk)
       return 0;
 
@@ -110,11 +109,10 @@ png_do_expand_palette_rgb8_neon(png_structrp png_ptr, png_row_infop row_info,
    png_uint_32 row_width = row_info->width;
    png_const_bytep palette = (png_const_bytep)png_ptr->palette;
    const png_uint_32 pixels_per_chunk = 8;
-   png_uint_32 i;
+   int i;
 
    png_debug(1, "in png_do_expand_palette_rgb8_neon");
 
-   PNG_UNUSED(row)
    if (row_width <= pixels_per_chunk)
       return 0;
 
diff --git a/pngread.c b/pngread.c
index 5ab922403..8fa7d9f16 100644
--- a/pngread.c
+++ b/pngread.c
@@ -3452,6 +3452,7 @@ png_image_read_background(png_voidp argument)
 
             for (pass = 0; pass < passes; ++pass)
             {
+               png_bytep row = png_voidcast(png_bytep, display->first_row);
                unsigned int     startx, stepx, stepy;
                png_uint_32      y;
 
@@ -3556,6 +3557,8 @@ png_image_read_background(png_voidp argument)
 
                         inrow += 2; /* gray and alpha channel */
                      }
+
+                     row += display->row_bytes;
                   }
                }
             }
diff --git a/pngrutil.c b/pngrutil.c
index ca060dd15..9ac8ec11f 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -2075,22 +2075,21 @@ png_handle_eXIf(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
       png_byte buf[1];
       png_crc_read(png_ptr, buf, 1);
       info_ptr->eXIf_buf[i] = buf[0];
-      if (i == 1)
+      if (i == 1 && buf[0] != 'M' && buf[0] != 'I'
+                 && info_ptr->eXIf_buf[0] != buf[0])
       {
-         if ((buf[0] != 'M' && buf[0] != 'I') ||
-             (info_ptr->eXIf_buf[0] != buf[0]))
-         {
-            png_crc_finish(png_ptr, length - 2);
-            png_chunk_benign_error(png_ptr, "incorrect byte-order specifier");
-            png_free(png_ptr, info_ptr->eXIf_buf);
-            info_ptr->eXIf_buf = NULL;
-            return;
-         }
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "incorrect byte-order specifier");
+         png_free(png_ptr, info_ptr->eXIf_buf);
+         info_ptr->eXIf_buf = NULL;
+         return;
       }
    }
 
-   if (png_crc_finish(png_ptr, 0) == 0)
-      png_set_eXIf_1(png_ptr, info_ptr, length, info_ptr->eXIf_buf);
+   if (png_crc_finish(png_ptr, 0) != 0)
+      return;
+
+   png_set_eXIf_1(png_ptr, info_ptr, length, info_ptr->eXIf_buf);
 
    png_free(png_ptr, info_ptr->eXIf_buf);
    info_ptr->eXIf_buf = NULL;
@@ -2126,9 +2125,8 @@ png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
 
    num = length / 2 ;
 
-   if (length != num * 2 ||
-       num != (unsigned int)png_ptr->num_palette ||
-       num > (unsigned int)PNG_MAX_PALETTE_LENGTH)
+   if (num != (unsigned int) png_ptr->num_palette ||
+       num > (unsigned int) PNG_MAX_PALETTE_LENGTH)
    {
       png_crc_finish(png_ptr, length);
       png_chunk_benign_error(png_ptr, "invalid");
@@ -4622,11 +4620,11 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
        */
       {
          png_bytep temp = png_ptr->big_row_buf + 32;
-         size_t extra = (size_t)temp & 0x0f;
+         int extra = (int)((temp - (png_bytep)0) & 0x0f);
          png_ptr->row_buf = temp - extra - 1/*filter byte*/;
 
          temp = png_ptr->big_prev_row + 32;
-         extra = (size_t)temp & 0x0f;
+         extra = (int)((temp - (png_bytep)0) & 0x0f);
          png_ptr->prev_row = temp - extra - 1/*filter byte*/;
       }
 #else
diff --git a/pngset.c b/pngset.c
index 8c372cf41..6444c0615 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1019,9 +1019,6 @@ png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
           info_ptr->trans_alpha = png_voidcast(png_bytep,
               png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH));
           memcpy(info_ptr->trans_alpha, trans_alpha, (size_t)num_trans);
-
-          info_ptr->valid |= PNG_INFO_tRNS;
-          info_ptr->free_me |= PNG_FREE_TRNS;
        }
        png_ptr->trans_alpha = info_ptr->trans_alpha;
    }
diff --git a/pngwrite.c b/pngwrite.c
index 06c45d16a..b9a0ca188 100644
--- a/pngwrite.c
+++ b/pngwrite.c
@@ -489,16 +489,6 @@ png_convert_from_time_t(png_timep ptime, time_t ttime)
    png_debug(1, "in png_convert_from_time_t");
 
    tbuf = gmtime(&ttime);
-   if (tbuf == NULL)
-   {
-      /* TODO: add a safe function which takes a png_ptr argument and raises
-       * a png_error if the ttime argument is invalid and the call to gmtime
-       * fails as a consequence.
-       */
-      memset(ptime, 0, sizeof(*ptime));
-      return;
-   }
-
    png_convert_from_struct_tm(ptime, tbuf);
 }
 #endif