Hi. It appears that upstream has not released Dia 0.97.3 yet, and it may take a while. Would it be possible if the Debian Dia Team picks the patch that fixes this before Jessie is released?
https://git.gnome.org/browse/dia/commit/?id=226fb87f34d4b49e700fb9cb340b49b67fd59540 Of course, the patch would have to be dropped once the next version is released for it not to FTBFS, but Dia would become useful again in the meanwhile, with benefit to all Debian-derived distributions. If we waited for the correct thing to happen, who knows when the kerning bug be fixed by the Pangocairo team. I attempted to pick the patch myself for the current version of the Debian Dia package. I am attaching the resulting dquilt patch. I tested debuild -us -uc and it builds. I installed the result to in system and it behaves correctly. Thanks.
--- a/plug-ins/cairo/diacairo-renderer.c +++ b/plug-ins/cairo/diacairo-renderer.c @@ -315,6 +315,15 @@ DIAG_STATE(DIA_CAIRO_RENDERER (self)->cr) } +/* There is a recurring bug with pangocairo related to kerning and font scaling. + * See: https://bugzilla.gnome.org/buglist.cgi?quicksearch=341481+573261+700592 + * Rather than waiting for another fix let's try to implement the ultimate work + * around. With Pango-1.32 and HarfBuzz the kludge in Pango is gone and apparently + * substituted with a precision problem. If we now use huge fonts when talking + * to Pango and downscale these with cairo it should work with all Pango versions. + */ +#define FONT_SIZE_TWEAK (72.0) + static void set_font(DiaRenderer *self, DiaFont *font, real height) { @@ -327,7 +336,7 @@ #ifdef HAVE_PANGOCAIRO_H /* select font and size */ - pango_font_description_set_absolute_size (pfd, (int)(size * PANGO_SCALE)); + pango_font_description_set_absolute_size (pfd, (int)(size * FONT_SIZE_TWEAK * PANGO_SCALE)); pango_layout_set_font_description (renderer->layout, pfd); pango_font_description_free (pfd); #else @@ -714,14 +723,17 @@ pango_layout_iter_get_line_extents (iter, NULL, &extents); shift = alignment == ALIGN_CENTER ? PANGO_RBEARING(extents)/2 : alignment == ALIGN_RIGHT ? PANGO_RBEARING(extents) : 0; + shift /= FONT_SIZE_TWEAK; + bline /= FONT_SIZE_TWEAK; cairo_move_to (renderer->cr, pos->x - (double)shift / PANGO_SCALE, pos->y - (double)bline / PANGO_SCALE); pango_layout_iter_free (iter); } /* does this hide bug #341481? */ - pango_cairo_update_context (renderer->cr, pango_layout_get_context (renderer->layout)); - pango_layout_context_changed (renderer->layout); + cairo_scale (renderer->cr, 1.0/FONT_SIZE_TWEAK, 1.0/FONT_SIZE_TWEAK); + pango_cairo_update_layout (renderer->cr, renderer->layout); pango_cairo_show_layout (renderer->cr, renderer->layout); + /* restoring the previous scale */ cairo_restore (renderer->cr); #else /* using the 'toy API' */
