configure: Improve help handling

To summerize my understanding of the help build:

LO can build three kinds of help: XML (local), HTML (local) and
HTML-online. Both local help variants can be included in help-
packs, which might be bundeled with the installer or provided as
separate packages. The HTML-online help is the external help
provided by help.libreoffice.org, which can provide an additional,
xapian-omega based, search mechanism. The XML help is build with
additional index and formating using internal tools. The xmlhelp
module is used to display the XML help. Both HTML-based help is
shown in a browser.

What this patch includes is:

* Adds --enable-xmlhelp for removing the xmlhelp support from the
build. Disable for iOS, Android and Emscripten. This was partly
included in HAVE_FEATURE_DESKTOP before.
* Rename WITH_HELP define to WITH_HELPPACKS, which reflects the
actual usage AFAIK.
* Depend --with-omindex on --with-help=online and don't override
the --with-help setting. Error out on conflicting options.
* Depend --with-helppack-integration on a build help variants,
which actually result in help packs.

Kind of reverts commit 2c38ea6d16b910294220cefaf8ae6a0683e6405a
("Building without --with-help is not supposed to disable help
functionality").

Change-Id: Ie4cb73905b3ed94e991d9f1bd75cfbd6de9da385

1 files changed, 94 insertions, 70 deletions

diff --git a/configure.ac b/configure.ac
index 32cc3e1b1dd0..b39e7c933ad5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -980,6 +980,7 @@ ios*) # iOS
     enable_postgresql_sdbc=no
     enable_extension_integration=no
     enable_report_builder=no
+    enable_xmlhelp=no
     with_ppds=no
     if test "$enable_ios_simulator" = "yes"; then
         host=x86_64-apple-darwin
@@ -1076,6 +1077,7 @@ linux-android*)
     enable_odk=no
     enable_postgresql_sdbc=no
     enable_python=no
+    enable_xmlhelp=no
     test_cups=no
     test_dbus=no
     test_fontconfig=no
@@ -1111,6 +1113,7 @@ emscripten)
     build_gstreamer_1_0=no
     enable_lpsolve=no
     enable_report_builder=no
+    enable_xmlhelp=no
     with_theme="breeze"
     test_cmis=no
     test_cups=no
@@ -1899,6 +1902,11 @@ AC_ARG_ENABLE(wasm-strip,
 ,enable_wasm_strip=yes)
 
 
+AC_ARG_ENABLE(xmlhelp,
+    AS_HELP_STRING([--disable-xmlhelp],
+        [Disable XML help support]),
+,enable_xmlhelp=yes)
+
 dnl ===================================================================
 dnl Optional Packages (--with/without-)
 dnl ===================================================================
@@ -5235,6 +5243,92 @@ fi
 AC_SUBST(PKGFORMAT)
 
 dnl ===================================================================
+dnl handle help related options
+dnl ===================================================================
+
+ENABLE_HTMLHELP=
+HELP_OMINDEX_PAGE=
+HELP_ONLINE=
+WITH_HELPPACKS=
+
+AC_MSG_CHECKING([which help to build])
+if test -n "$with_help" -a "$with_help" != "no"; then
+    GIT_NEEDED_SUBMODULES="helpcontent2 $GIT_NEEDED_SUBMODULES"
+    BUILD_TYPE="$BUILD_TYPE HELP"
+    case "$with_help" in
+    "html")
+        ENABLE_HTMLHELP=TRUE
+        WITH_HELPPACKS=TRUE
+        SCPDEFS="$SCPDEFS -DWITH_HELPPACKS"
+        AC_MSG_RESULT([HTML (local)])
+        ;;
+    "online")
+        ENABLE_HTMLHELP=TRUE
+        HELP_ONLINE=TRUE
+        AC_MSG_RESULT([HTML (online)])
+        ;;
+    yes)
+        WITH_HELPPACKS=TRUE
+        SCPDEFS="$SCPDEFS -DWITH_HELPPACKS"
+        BUILD_TYPE="$BUILD_TYPE HELPTOOLS"
+        AC_MSG_RESULT([XML (local)])
+        ;;
+    *)
+        AC_MSG_ERROR([Unknown --with-help=$with_help])
+        ;;
+    esac
+else
+    AC_MSG_RESULT([no])
+fi
+
+AC_MSG_CHECKING([whether to enable xapian-omega support for online help])
+if test -n "$with_omindex" -a "$with_omindex" != "no"; then
+    if test "$HELP_ONLINE" != TRUE; then
+        AC_MSG_ERROR([Can't build xapian-omega index without --help=online])
+    fi
+    case "$with_omindex" in
+    "server")
+        HELP_OMINDEX_PAGE=TRUE
+        AC_MSG_RESULT([SERVER])
+        ;;
+    "noxap")
+        AC_MSG_RESULT([NOXAP])
+        ;;
+    *)
+        AC_MSG_ERROR([Unknown --with-omindex=$with_omindex])
+        ;;
+    esac
+else
+    AC_MSG_RESULT([no])
+fi
+
+AC_MSG_CHECKING([whether to include the XML-help support])
+if test "$enable_xmlhelp" = yes; then
+    BUILD_TYPE="$BUILD_TYPE XMLHELP"
+    AC_DEFINE(HAVE_FEATURE_XMLHELP)
+    AC_MSG_RESULT([yes])
+else
+    if test "$with_help" = yes; then
+        add_warning "Building the XML help, but LO with disabled xmlhelp support. Generated help can't be accesssed from this LO build!"
+    fi
+    AC_MSG_RESULT([no])
+fi
+
+dnl Test whether to integrate helppacks into the product's installer
+AC_MSG_CHECKING([for helppack integration])
+if test -z "$WITH_HELPPACKS" -o "$with_helppack_integration" = no; then
+    AC_MSG_RESULT([no integration])
+else
+    SCPDEFS="$SCPDEFS -DWITH_HELPPACK_INTEGRATION"
+    AC_MSG_RESULT([integration])
+fi
+
+AC_SUBST([ENABLE_HTMLHELP])
+AC_SUBST([HELP_OMINDEX_PAGE])
+AC_SUBST([HELP_ONLINE])
+# WITH_HELPPACKS is used only in configure
+
+dnl ===================================================================
 dnl Set up a different compiler to produce tools to run on the build
 dnl machine when doing cross-compilation
 dnl ===================================================================
@@ -5666,65 +5760,6 @@ else
 fi
 AC_SUBST(DO_FETCH_TARBALLS)
 
-AC_MSG_CHECKING([whether to build help])
-if test -n "$with_help" -a "$with_help" != "no" -a $_os != iOS -a $_os != Android; then
-    BUILD_TYPE="$BUILD_TYPE HELP"
-    GIT_NEEDED_SUBMODULES="helpcontent2 $GIT_NEEDED_SUBMODULES"
-    case "$with_help" in
-    "html")
-        ENABLE_HTMLHELP=TRUE
-        SCPDEFS="$SCPDEFS -DWITH_HELP"
-        AC_MSG_RESULT([HTML])
-        ;;
-    "online")
-        ENABLE_HTMLHELP=TRUE
-        HELP_ONLINE=TRUE
-        AC_MSG_RESULT([HTML])
-        ;;
-    yes)
-        SCPDEFS="$SCPDEFS -DWITH_HELP"
-        AC_MSG_RESULT([yes])
-        ;;
-    *)
-        AC_MSG_ERROR([Unknown --with-help=$with_help])
-        ;;
-    esac
-else
-    AC_MSG_RESULT([no])
-fi
-AC_SUBST([ENABLE_HTMLHELP])
-AC_SUBST([HELP_ONLINE])
-
-AC_MSG_CHECKING([whether to enable xapian-omega support for help])
-if test -n "$with_omindex" -a "$with_omindex" != "no" -a $_os != iOS -a $_os != Android; then
-    BUILD_TYPE="$BUILD_TYPE HELP"
-    GIT_NEEDED_SUBMODULES="helpcontent2 $GIT_NEEDED_SUBMODULES"
-    case "$with_omindex" in
-    "server")
-        ENABLE_HTMLHELP=TRUE
-        HELP_ONLINE=TRUE
-        HELP_OMINDEX_PAGE=TRUE
-        AC_MSG_RESULT([SERVER])
-        ;;
-    "noxap")
-        ENABLE_HTMLHELP=TRUE
-        HELP_ONLINE=TRUE
-        HELP_OMINDEX_PAGE=FALSE
-        AC_MSG_RESULT([NOXAP])
-        ;;
-    *)
-        AC_MSG_ERROR([Unknown --with-omindex=$with_omindex])
-        ;;
-    esac
-else
-    HELP_OMINDEX_PAGE=FALSE
-    AC_MSG_RESULT([no])
-fi
-AC_SUBST([ENABLE_HTMLHELP])
-AC_SUBST([HELP_OMINDEX_PAGE])
-AC_SUBST([HELP_ONLINE])
-
-
 dnl Test whether to include MySpell dictionaries
 dnl ===================================================================
 AC_MSG_CHECKING([whether to include MySpell dictionaries])
@@ -12836,17 +12871,6 @@ for theme in $with_theme; do
     esac
 done
 
-dnl ===================================================================
-dnl Test whether to integrate helppacks into the product's installer
-dnl ===================================================================
-AC_MSG_CHECKING([for helppack integration])
-if test "$with_helppack_integration" = "no"; then
-    AC_MSG_RESULT([no integration])
-else
-    SCPDEFS="$SCPDEFS -DWITH_HELPPACK_INTEGRATION"
-    AC_MSG_RESULT([integration])
-fi
-
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 # Extensions checking
 ###############################################################################