WIP use Homebrew libiconv

Author: ychin

.github/workflows/macvim-buildtest.yaml

@@ -222,6 +222,9 @@ jobs:
             sed -i.bak -f ci/config.mk.optimized.sed src/auto/config.mk
           fi
 
+          # Use Homebrew libiconv since Apple iconv is broken since macOS 14
+          sed -i.bak -f ci/config.mk.brew-libiconv.sed src/auto/config.mk
+
       - name: Modify configure result
         if: inputs.publish
         run: |

ci/config.mk.brew-libiconv.sed

@@ -0,0 +1,7 @@
+# Use Homebrew libiconv to work around broken Apple version. Use static linking
+# as we don't want our binary releases to pull in third-party dependencies.
+#
+# If gettext is configured in the build, this only works libintl is also built
+# against Homebrew libiconv (which is not the default in Homebrew).
+/^CFLAGS[[:blank:]]*=/s/$/ -I\/opt\/homebrew\/opt\/libiconv\/include/
+/^LIBS[[:blank:]]*=/s/-liconv/\/opt\/homebrew\/opt\/libiconv\/lib\/libiconv.a/