Minor improvements (#2556)

- Remove unused libgif-dev dependency from CI.
- Remove no longer relevant comment from testsuite.
- Use yes/no instead of boolean values in configure.ac.

.github/workflows/ci.yml

@@ -69,9 +69,9 @@ jobs:
             libheif-dev libexpat1-dev libcfitsio-dev
             libmatio-dev libnifti-dev liborc-0.4-dev
             liblcms2-dev libpoppler-glib-dev librsvg2-dev
-            libgif-dev libopenexr-dev libpango1.0-dev
-            libgsf-1-dev libopenslide-dev libffi-dev
-            libopenjp2-7-dev libimagequant-dev libcgif-dev
+            libopenexr-dev libpango1.0-dev libgsf-1-dev
+            libopenslide-dev libffi-dev libopenjp2-7-dev
+            libimagequant-dev libcgif-dev
 
       - name: Install macOS dependencies
         if: runner.os == 'macOS'

configure.ac

@@ -58,11 +58,11 @@ AC_SUBST(LIBRARY_REVISION)
 AC_SUBST(LIBRARY_AGE)
 
 # init introspection support
-have_introspection=false
+have_introspection=no
 m4_ifdef([GOBJECT_INTROSPECTION_CHECK], [
     GOBJECT_INTROSPECTION_CHECK([1.30.0])
     if test "x$found_introspection" = x"yes"; then
-        have_introspection=true
+        have_introspection=yes
     fi
 ], [
     AM_CONDITIONAL([HAVE_INTROSPECTION], false)

test/test-suite/test_foreign.py

@@ -768,8 +768,7 @@ class TestForeign:
                 y = pyvips.Image.new_from_buffer(buf, "")
                 assert y.get("orientation") == 6
 
-        # try converting an animated gif to webp ... can't do back to gif
-        # again without IM support
+        # try converting an animated gif to webp
         if have("gifload"):
             x1 = pyvips.Image.new_from_file(GIF_ANIM_FILE, n=-1)
             w1 = x1.webpsave_buffer(Q=10)