[goffice] Don't try to display an image with nul size in the canvas.

[Jean Bréfort <jbrefort src gnome org>]

commit 08ba6dd9bea422371bc80e4d57f5a8a4dfbca69c
Author: Jean Brefort <jean brefort normalesup org>
Date:   Wed Feb 14 16:19:31 2018 +0100

    Don't try to display an image with nul size in the canvas.

 ChangeLog                  |    7 +++++++
 goffice/canvas/goc-image.c |   16 +++++++++++-----
 goffice/utils/go-emf.c     |    8 ++++++--
 3 files changed, 24 insertions(+), 7 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index ac1f23d..9586f0d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2018-02-14  Jean Brefort  <jean brefort normalesup org>
+
+       * goffice/canvas/goc-image.c (goc_image_draw): don't try to display an image
+       with nul size.
+       * goffice/utils/go-emf.c (go_emf_lineto): create a path if necessary instead
+       of returning an error.
+
 2017-12-28  Morten Welinder <terra gnome org>
 
        * configure.ac: Post-release bump.
diff --git a/goffice/canvas/goc-image.c b/goffice/canvas/goc-image.c
index ce58977..8c0c880 100644
--- a/goffice/canvas/goc-image.c
+++ b/goffice/canvas/goc-image.c
@@ -214,25 +214,31 @@ static void
 goc_image_draw (GocItem const *item, cairo_t *cr)
 {
        GocImage *image = GOC_IMAGE (item);
-       double height, width;
+       double height, width, iw, ih;
        double scalex = 1., scaley = 1.;
        int x;
 
        if (image->image == NULL || image->width == 0. || image->height == 0.)
                return;
 
+       iw = go_image_get_width (image->image);
+       ih = go_image_get_height (image->image);
+       if (iw == 0. || ih == 0.)
+           return;
+
        if (image->width < 0.)
-               width = go_image_get_width (image->image) * (1 - image->crop_left -image->crop_right);
+               width = iw * (1 - image->crop_left -image->crop_right);
        else {
                width = image->width;
-               scalex = width / go_image_get_width (image->image) / (1 - image->crop_left 
-image->crop_right);
+               scalex = width / iw / (1 - image->crop_left -image->crop_right);
        }
        if (image->height < 0.)
-               height = go_image_get_height (image->image) * (1 - image->crop_top -image->crop_bottom);
+               height = ih * (1 - image->crop_top -image->crop_bottom);
        else {
                height = image->height;
-               scaley = height / go_image_get_height (image->image) / (1 - image->crop_top 
-image->crop_bottom);
+               scaley = height / ih / (1 - image->crop_top -image->crop_bottom);
        }
+
        cairo_save (cr);
        _goc_item_transform (item, cr, TRUE);
        x = (goc_canvas_get_direction (item->canvas) == GOC_DIRECTION_RTL)?
diff --git a/goffice/utils/go-emf.c b/goffice/utils/go-emf.c
index 9790466..017c818 100644
--- a/goffice/utils/go-emf.c
+++ b/goffice/utils/go-emf.c
@@ -3818,8 +3818,12 @@ go_emf_lineto (GOEmfState *state)
 {
        double x, y;
        d_(("lineto\n"));
-       if (state->curDC->path == NULL)
-               return FALSE;
+       if (state->curDC->path == NULL) {
+               state->curDC->path = go_path_new ();
+               go_path_move_to (state->curDC->path,
+                                state->curDC->xpos,
+                                state->curDC->ypos);
+       }
        go_wmf_read_pointl (state->data, &x, &y);
        go_emf_convert_coords (state, &x, &y);
        go_path_line_to (state->curDC->path, x, y);