[gimp/gimp-2-10] plug-ins: fix reading of psp tubes when psp file version >= 4.

[Jehan <jehanp src gnome org>]

commit 146a8d644bcaeb33c6f45d70ce7eb6edbd2d0d8b
Author: Jacob Boerema <jgboerema gmail com>
Date:   Wed Aug 26 19:09:28 2020 -0400

    plug-ins: fix reading of psp tubes when psp file version >= 4.
    
    (cherry picked from commit b968a93ab2d196a81729dd1b2cbfa47351c0c47c)

 plug-ins/common/file-psp.c | 46 ++++++++++++++++++++++++++++++++++------------
 1 file changed, 34 insertions(+), 12 deletions(-)
---
diff --git a/plug-ins/common/file-psp.c b/plug-ins/common/file-psp.c
index 56723d2863..1e2eb36c1d 100644
--- a/plug-ins/common/file-psp.c
+++ b/plug-ins/common/file-psp.c
@@ -1770,6 +1770,7 @@ read_tube_block (FILE      *f,
   guchar             name[514];
   guint32            step_size, column_count, row_count, cell_count;
   guint32            placement_mode, selection_mode;
+  guint32            chunk_len;
   gint               i;
   GimpPixPipeParams  params;
   GimpParasite      *pipe_parasite;
@@ -1777,21 +1778,42 @@ read_tube_block (FILE      *f,
 
   gimp_pixpipe_params_init (&params);
 
-  if (fread (&version, 2, 1, f) < 1
-      || fread (name, 513, 1, f) < 1
-      || fread (&step_size, 4, 1, f) < 1
-      || fread (&column_count, 4, 1, f) < 1
-      || fread (&row_count, 4, 1, f) < 1
-      || fread (&cell_count, 4, 1, f) < 1
-      || fread (&placement_mode, 4, 1, f) < 1
-      || fread (&selection_mode, 4, 1, f) < 1)
+  if (psp_ver_major >= 4)
     {
-      g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
-                   _("Error reading tube data chunk"));
-      return -1;
+      name[0] = 0;
+      if (fread (&chunk_len, 4, 1, f) < 1
+          || fread (&version, 2, 1, f) < 1
+          || fread (&step_size, 4, 1, f) < 1
+          || fread (&column_count, 4, 1, f) < 1
+          || fread (&row_count, 4, 1, f) < 1
+          || fread (&cell_count, 4, 1, f) < 1
+          || fread (&placement_mode, 4, 1, f) < 1
+          || fread (&selection_mode, 4, 1, f) < 1)
+        {
+          g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
+                       _("Error reading tube data chunk"));
+          return -1;
+        }
+    }
+  else
+    {
+      chunk_len = 0;
+      if (fread (&version, 2, 1, f) < 1
+          || fread (name, 513, 1, f) < 1
+          || fread (&step_size, 4, 1, f) < 1
+          || fread (&column_count, 4, 1, f) < 1
+          || fread (&row_count, 4, 1, f) < 1
+          || fread (&cell_count, 4, 1, f) < 1
+          || fread (&placement_mode, 4, 1, f) < 1
+          || fread (&selection_mode, 4, 1, f) < 1)
+        {
+          g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
+                       _("Error reading tube data chunk"));
+          return -1;
+        }
+      name[513] = 0;
     }
 
-  name[513] = 0;
   version = GUINT16_FROM_LE (version);
   params.step = GUINT32_FROM_LE (step_size);
   params.cols = GUINT32_FROM_LE (column_count);