non-interactive diff now exits with 0 if no differences, 1 if differences

3 files changed, 12 insertions, 7 deletions

diff --git a/TODO b/TODO
index 8c87e09..9975a22 100644
--- a/TODO
+++ b/TODO
@@ -34,7 +34,6 @@ Rendering:
 - support line thickness ?
 - ~ as overline (grep for ~ in out.fig) [ done for Cairo, FIG still missing ]
 - maybe let user set PNG size [we have zoom level]
-- return indication of whether non-interactive diff found any differences
 - in diff, pass only options understood by cairo_png
 - find out why in Cairo PDF non-dashed lines disappear if CAIRO_LINE_CAP_ROUND
 - diff area algorithm will fill anything resembling a closed path, no matter
diff --git a/gfx/diff.c b/gfx/diff.c
index e9d6273..a00e928 100644
--- a/gfx/diff.c
+++ b/gfx/diff.c
@@ -370,7 +370,7 @@ static void merge_coord(int pos_a, int pos_b, int dim_a, int dim_b,
 static cairo_t *make_diff(cairo_t *cr, int cx, int cy, float scale,
     struct cro_ctx *old, struct cro_ctx *old_extra,
     struct cro_ctx *new, struct cro_ctx *new_extra,
-    const struct area *areas)
+    const struct area *areas, bool *changed)
 {
 	int old_xmin, old_ymin, old_w, old_h;
 	int new_xmin, new_ymin, new_w, new_h;
@@ -420,7 +420,10 @@ static cairo_t *make_diff(cairo_t *cr, int cx, int cy, float scale,
 	cairo_surface_flush(s);
 	differences(&diff, img_old, img_new);
 	show_areas(&diff, img_old);
+	if (changed)
+		*changed = diff.areas;
 	free_areas(&diff.areas);
+
 	if (areas) {
 		diff.areas = (struct area *) areas;
 		show_areas(&diff, img_old);
@@ -439,12 +442,14 @@ static int diff_end(void *ctx)
 	struct diff *diff = ctx;
 	cairo_t *old_cr;
 	cairo_surface_t *s;
+	bool changed;
 
 	assert(diff->gfx);
 	assert(diff->new_gfx);
 
 	old_cr = make_diff(NULL, 0, 0, diff->scale,
-	    gfx_user(diff->gfx), NULL, gfx_user(diff->new_gfx), NULL, NULL);
+	    gfx_user(diff->gfx), NULL, gfx_user(diff->new_gfx), NULL, NULL,
+	    &changed);
 	s = cairo_get_target(old_cr);
 
 	cro_img_write(s, diff->output_name);
@@ -452,7 +457,7 @@ static int diff_end(void *ctx)
 	cairo_surface_destroy(s);
 	cairo_destroy(old_cr);
 
-	return 0;
+	return changed;
 }
 
 
@@ -468,7 +473,7 @@ void diff_to_canvas(cairo_t *cr, int cx, int cy, float scale,
 	cairo_surface_t *s;
 
 	old_cr = make_diff(cr, cx, cy, scale, old, old_extra, new, new_extra,
-	    areas);
+	    areas, NULL);
 
 	s = cairo_get_target(old_cr);
 	cairo_set_source_surface(cr, s, 0, 0);
diff --git a/main.c b/main.c
index 1172381..fddd9fa 100644
--- a/main.c
+++ b/main.c
@@ -141,6 +141,7 @@ int main(int argc, char **argv)
 	char **gfx_argv;
 	const struct gfx_ops **ops = ops_list;
 	struct gfx *gfx;
+	int retval;
 
 	if (argc > 1 && !strcmp(argv[1], "gdb")) {
 		char **args;
@@ -335,10 +336,10 @@ found:
 		if (pl)
 			pl_render(pl, gfx, sch_ctx.sheets, sch_ctx.sheets);
 	}
-	gfx_end(gfx);
+	retval = gfx_end(gfx);
 
 	sch_free(&sch_ctx);
 	lib_free(&lib);
 
-	return 0;
+	return retval;
 }