[gimp] configure: improve libheif detection and output.

[Jehan <jehanp src gnome org>]

commit 41285813a599e1902cd2e75cc69a0550c21b8b3f
Author: Jehan <jehan girinstud io>
Date:   Tue Nov 12 14:48:26 2019 +0100

    configure: improve libheif detection and output.
    
    Replace the "Heif >= 1.4.0" line in the summary output by a comment in
    the "Heif" line explaining this is about profile support.
    
    Also add a >= 1.6.0 test and output a warning for Windows and macOS (cf.
    bug #4185).

 configure.ac | 37 +++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 532c7ebfbf..7c70eafad8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1789,27 +1789,45 @@ AM_CONDITIONAL(HAVE_WEBP, test "x$have_webp" = xyes)
 AC_ARG_WITH(libheif, [  --without-libheif       build without libheif support])
 
 have_libheif=no
+have_libheif_1_4_0=no
+have_libheif_1_6_0=no
 if test "x$with_libheif" != xno; then
   have_libheif_1_4_0=yes
+  have_libheif_1_6_0=yes
   have_libheif=yes
-  PKG_CHECK_MODULES(LIBHEIF, libheif >= 1.4.0,,
-    [have_libheif_1_4_0="no (libheif >= 1.4.0 not found)"])
-  PKG_CHECK_MODULES(LIBHEIF, libheif >= libheif_required_version,
-    FILE_HEIF='file-heif$(EXEEXT)',
-    [have_libheif="no (libheif not found)"])
+  PKG_CHECK_MODULES(LIBHEIF, libheif >= 1.6.0,,
+    [
+      have_libheif_1_6_0="no (libheif >= 1.6.0 not found)"
+      PKG_CHECK_MODULES(LIBHEIF, libheif >= 1.4.0,,
+        [
+          have_libheif_1_4_0="no (libheif >= 1.4.0 not found)"
+          PKG_CHECK_MODULES(LIBHEIF, libheif >= libheif_required_version,
+                            FILE_HEIF='file-heif$(EXEEXT)',
+                            [have_libheif="no (libheif not found)"])
+        ])
+    ])
 fi
 
+AC_SUBST(FILE_HEIF)
+AM_CONDITIONAL(HAVE_LIBHEIF, test "x$have_libheif" = xyes)
+
 if test "x$have_libheif" = xyes; then
   MIME_TYPES="$MIME_TYPES;image/heif;image/heic"
+  have_libheif="yes [[profile support: $have_libheif_1_4_0]]"
 fi
 
-AC_SUBST(FILE_HEIF)
-AM_CONDITIONAL(HAVE_LIBHEIF, test "x$have_libheif" = xyes)
-
 if test "x$have_libheif_1_4_0" = xyes; then
   AC_DEFINE(HAVE_LIBHEIF_1_4_0, 1,
             [Define to 1 if libheif >= 1.4.0 is available])
 fi
+if test "x$have_libheif_1_6_0" = xyes; then
+  AC_DEFINE(HAVE_LIBHEIF_1_6_0, 1,
+            [Define to 1 if libheif >= 1.6.0 is available])
+elif test "x$platform_win32" = xyes || test "x$platform_osx" = xyes; then
+          warning_libheif="
+WARNING: libheif lower than version 1.6.0 are known to crash when
+         exporting on Windows and macOS (bug #4185). Please update."
+fi
 
 
 ########################
@@ -3134,7 +3152,6 @@ Optional Plug-Ins:
   OpenEXR:                   $have_openexr
   WebP:                      $have_webp
   Heif:                      $have_libheif
-  Heif >= 1.4.0:             $have_libheif_1_4_0
   PDF (export):              $have_cairo_pdf
   Print:                     $enable_print
   Python 3 plug-ins:         $with_python
@@ -3158,7 +3175,7 @@ Tests:
   Test desktop file          $have_desktop_file_validate
 
 Bug report URL: $with_bug_report_url
-$override_bug_report_url$warning_vector_icons_windows$warning_glib_networking$warning_gcc$warning_python$warning_javascript$warning_lua"
+$override_bug_report_url$warning_vector_icons_windows$warning_glib_networking$warning_gcc$warning_python$warning_javascript$warning_lua$warning_libheif"
 
 if test "x$required_deps" = "x"; then
   AC_OUTPUT