From 03ea666fc8e96bdf9a2d91349fd010bf9040a461 Mon Sep 17 00:00:00 2001
From: Alx Sa <cmyk.student@gmail.com>
Date: Thu, 29 Jun 2023 15:31:50 +0000
Subject: [PATCH] plug-ins: Fix regression on importing RGB FITS

The developers of SiriL sent me some RGB FITS images that rendered incorrectly
after d4f42076. These must be read in as
planes rather than individual rows.
---
 plug-ins/file-fits/fits.c | 77 +++++++++++++++++++++++++--------------
 1 file changed, 50 insertions(+), 27 deletions(-)

diff --git a/plug-ins/file-fits/fits.c b/plug-ins/file-fits/fits.c
index 955ea6d15b..a6f941cc6d 100644
--- a/plug-ins/file-fits/fits.c
+++ b/plug-ins/file-fits/fits.c
@@ -502,8 +502,12 @@ load_image (GFile        *file,
                                     NULL);
         }
 
-      /* If RGB FITS image, we need to increase the size by the number of channels */
-      pixels = (gdouble *) malloc (width * sizeof (gdouble) * channels);
+      /* If RGB FITS image, we need to read in the whole image so we can convert
+       * the planes format to RGB */
+      if (hdu.naxis == 2)
+        pixels = (gdouble *) malloc (width * sizeof (gdouble) * channels);
+      else
+        pixels = (gdouble *) malloc (width * height * sizeof (gdouble) * channels);
 
       if (! image)
         {
@@ -543,41 +547,60 @@ load_image (GFile        *file,
         show_fits_errors (status);
 
       /* Read pixel values in */
-      for (fpixel[1] = height; fpixel[1] >= 1; fpixel[1]--)
+      if (hdu.naxis == 2)
         {
-          gdouble *temp =
-            (gdouble *) malloc (width * sizeof (gdouble) * channels);
-
-          if (fits_read_pix (ifp, TDOUBLE, fpixel, row_length, &replace_val,
-                             pixels, NULL, &status))
-            break;
-
-          if (datamin < datamax)
+          for (fpixel[1] = height; fpixel[1] >= 1; fpixel[1]--)
             {
-              for (gint ii = 0; ii < row_length; ii++)
-                pixels[ii] = (pixels[ii] - datamin) / (datamax - datamin);
+              if (fits_read_pix (ifp, TDOUBLE, fpixel, row_length, &replace_val,
+                                 pixels, NULL, &status))
+                break;
+
+              if (datamin < datamax)
+                {
+                  for (gint ii = 0; ii < row_length; ii++)
+                    pixels[ii] = (pixels[ii] - datamin) / (datamax - datamin);
+                }
+
+              gegl_buffer_set (buffer,
+                               GEGL_RECTANGLE (0, height - fpixel[1],
+                                               width, 1), 0,
+                               format, pixels, GEGL_AUTO_ROWSTRIDE);
             }
+        }
+      else if (hdu.naxisn[2] && hdu.naxisn[2] == 3)
+        {
+          gint total_size = width * height * channels;
 
-          if (hdu.naxisn[2] && hdu.naxisn[2] == 3) /* Packed RGB format */
+          fits_read_img (ifp, TDOUBLE, 1, total_size, &replace_val,
+                         pixels, NULL, &status);
+
+          if (! status)
             {
-              /* Cover planes to RGB format */
-              for (gint ii = 0; ii < (row_length / 3); ii++)
+              gdouble *temp;
+
+              temp = (gdouble *) malloc (width * height * sizeof (gdouble) * channels);
+
+              if (datamin < datamax)
+                {
+                  for (gint ii = 0; ii < total_size; ii++)
+                    pixels[ii] = (pixels[ii] - datamin) / (datamax - datamin);
+                }
+
+              for (gint ii = 0; ii < (total_size / 3); ii++)
                 {
                   temp[(ii * 3)]     = pixels[ii];
-                  temp[(ii * 3) + 1] = pixels[ii + (row_length / 3)];
-                  temp[(ii * 3) + 2] = pixels[ii + ((row_length / 3) * 2)];
+                  temp[(ii * 3) + 1] = pixels[ii + (total_size / 3)];
+                  temp[(ii * 3) + 2] = pixels[ii + ((total_size / 3) * 2)];
                 }
-            }
-          else
-            {
-              temp = pixels;
-            }
 
-          gegl_buffer_set (buffer,
-                           GEGL_RECTANGLE (0, height - fpixel[1],
-                                           width, 1), 0,
-                           format, temp, GEGL_AUTO_ROWSTRIDE);
+              gegl_buffer_set (buffer, GEGL_RECTANGLE (0, 0, width, height), 0,
+                               format, temp, GEGL_AUTO_ROWSTRIDE);
+
+              if (temp)
+                g_free (temp);
+            }
         }
+
       if (status)
         show_fits_errors (status);