fix building with new libxml 2.12.0

[kloczek]

Added include <libxml/xmlsave.h> to allow build with libxml 2.12.0.

This PR fixes buid issue with libxml 2.12.0

make[4]: Entering directory '/home/tkloczko/rpmbuild/BUILD/eom-1.27.1/cut-n-paste/toolbar-editor'
  CC       libtoolbareditor_la-egg-toolbars-model.lo
egg-toolbars-model.c: In function 'egg_toolbars_model_to_xml':
egg-toolbars-model.c:78:3: error: 'xmlIndentTreeOutput' undeclared (first use in this function)
   78 |   xmlIndentTreeOutput = TRUE;
      |   ^~~~~~~~~~~~~~~~~~~
egg-toolbars-model.c:78:3: note: each undeclared identifier is reported only once for each function it appears in
egg-toolbars-model.c: In function 'egg_toolbars_model_load_toolbars':
egg-toolbars-model.c:591:9: warning: implicit declaration of function 'xmlParseFile'; did you mean 'xmlSaveFile'? [-Wimplicit-function-declaration]
  591 |   doc = xmlParseFile (xml_file);
      |         ^~~~~~~~~~~~
      |         xmlSaveFile
egg-toolbars-model.c:591:7: warning: assignment to 'xmlDocPtr' {aka 'struct _xmlDoc *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]
  591 |   doc = xmlParseFile (xml_file);
      |       ^
egg-toolbars-model.c: In function 'egg_toolbars_model_load_names':
egg-toolbars-model.c:655:7: warning: assignment to 'xmlDocPtr' {aka 'struct _xmlDoc *'} from 'int' makes pointer from integer without a cast [-Wint-conversion]
  655 |   doc = xmlParseFile (xml_file);
      |       ^
make[4]: *** [Makefile:574: libtoolbareditor_la-egg-toolbars-model.lo] Error 1

[raveit65]

Fedora 39 CI build failed because of new libpeas-2 which comes with API and ABI changes and and removal of the GTK interfaces. See libpeas migration guide https://gitlab.gnome.org/GNOME/libpeas/-/commit/80ccc392922289f69d5a705f808e25818ceae1a9 Of cause i can't build eom for stable fedora 39 anymore :/

Debian CI use libxml2-dev/testing,now 2.9.14+dfsg-1.3 amd64 see https://app.travis-ci.com/github/mate-desktop/eom/jobs/613603820#L389

In result i have no idea to test this PR at the moment.

@mate-desktop/core-team Any ideas?

[cwendling]

Short of building from source, I don't know.

However, the change look roughly OK, but does it fix the implicit declaration of function 'xmlParseFile' issue? It's not a hard error here, but it's a terrible thing to let pass (I myself always build with -Werror-implicit-function-delcaration because of this silly C89 feature). IIUC, you'd have to include libxml/parser.h.

Also, I'd actually include libxml/globals.h instead of libxml/xmlsave.h for getting xmlIndentTreeOutput, as it's here it is in pre-2.12, and it's supported by 2.12 as well.

Note: I did not build with libxml2 2.12, I just looked at the new sources.

[kloczek]

However, the change look roughly OK, but does it fix the implicit declaration of function 'xmlParseFile' issue? It's not a hard error here, but it's a terrible thing to let pass (I myself always build with -Werror-implicit-function-delcaration because of this silly C89 feature). IIUC, you'd have to include libxml/parser.h.

Please never do such things if you don't want to shoot in your own foot.

[cwendling]

Please never do such things if you don't want to shoot in your own foot.

@kloczek what to you mean? Never do what?

[raveit65]

I tested your commit with eom rpm in fedora-rawhide which comes with libxml2-devel-2.12.0-1.fc40.x86_64. Compiling fails with

currency-manager.c: In function ‘load_ecb_rates’:
currency-manager.c:484:5: error: implicit declaration of function ‘xmlInitParser’ [-Werror=implicit-function-declaration]
484 |     xmlInitParser();
|     ^~~~~~~~~~~~~
currency-manager.c:486:16: error: implicit declaration of function ‘xmlReadFile’ [-Werror=implicit-function-declaration]
486 |     document = xmlReadFile(filename, NULL, 0);
|                ^~~~~~~~~~~
currency-manager.c:486:14: warning: assignment to ‘xmlDocPtr’ {aka ‘struct _xmlDoc *’} from ‘int’ makes pointerfrom integer without a cast [-Wint-conversion]
486 |     document = xmlReadFile(filename, NULL, 0);
|              ^
gcc -DHAVE_CONFIG_H -I. -I..  -DLOCALE_DIR=\""/usr/share/locale"\" -Wall -Wmissing-prototypes -I/usr/include/pango-1.0 -I/usr/include/gtk-3.0 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/cairo -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -I/usr/include/atk-1.0 -I/usr/include/libxml2 -I/usr/include/harfbuzz -I/usr/include/freetype2 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/at-spi2-atk/2.0 -I/usr/include/cloudproviders -I/usr/include/webp -I/usr/include/at-spi-2.0 -I/usr/include/gio-unix-2.0 -I/usr/include/blkid -I/usr/include/pixman-1 -I/usr/include/libmount -I/usr/include/fribidi -I/usr/include/libpng16 -I/usr/include/sysprof-6 -pthread   -O2 -flto=auto -ffat-lto-objects -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Werror=implicit-function-declaration -Werror=implicit-int -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1  -m64   -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer  -c -o mp-trigonometric.o mp-trigonometric.c
currency-manager.c:524:5: error: implicit declaration of function ‘xmlCleanupParser’ [-Werror=implicit-function-declaration]
524 |     xmlCleanupParser();
|     ^~~~~~~~~~~~~~~~

Sadly, i wasn't able to add -Werror=implicit-function-declaration or -Wimplicit-function-declaration when compiling locally with autotools to reproduce this warning. Using CFLAGS='-O2 -g -pipe -Wall -Werror=format-security -Wimplicit-function-declaration -Werror=implicit-int' ./autogen.sh doesn't have any effect in fedora 38/39.

[raveit65]

CI is fixed https://github.com/mate-desktop/eom/commit/768f2bbd2a11d2d4c88a512dff9df6342bdc40b7 You can rebase branch. But fedora39 use libxml-2.10.4-3.fc39. So, this doesn't test your PR.

[kloczek]

@kloczek what to you mean? Never do what?

This is not place to explain that. it is set of very good reasons to not ignore such warnings.

[cwendling]

it is set of very good reasons to not ignore such warnings.

What I wrote is that you should treat implicit function declaration as an error, definitely not ignore it.

[kloczek]

What I wrote is that you should treat implicit function declaration as an error, definitely not ignore it.

OK. Sorry my fault .. misunderstanding.

[raveit65]

Cool, with the new rebase branch with master suggestion button we can rebase PR for our self now ;)

[lukefromdc]

We have libxml2.9 in Debian Unstable right now

[cwendling]

OK so I just tested this with 2.12.0.

With the current state of this PR, I still get this:

egg-toolbars-model.c: In function ‘egg_toolbars_model_load_toolbars’:
egg-toolbars-model.c:592:9: warning: implicit declaration of function ‘xmlParseFile’; did you mean ‘xmlSaveFile’? [-Wimplicit-function-declaration]
  592 |   doc = xmlParseFile (xml_file);
      |         ^~~~~~~~~~~~
      |         xmlSaveFile
egg-toolbars-model.c:592:7: warning: assignment to ‘xmlDocPtr’ {aka ‘struct _xmlDoc *’} from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
  592 |   doc = xmlParseFile (xml_file);
      |       ^
egg-toolbars-model.c: In function ‘egg_toolbars_model_load_names’:
egg-toolbars-model.c:656:7: warning: assignment to ‘xmlDocPtr’ {aka ‘struct _xmlDoc *’} from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
  656 |   doc = xmlParseFile (xml_file);
      |       ^

which is not good.

With my suggestion though all warnings are gone (for me), and it builds fine with both 2.9.14 and 2.12.0.