From d9ad0fb982203ea669eedf0fd504638b8a37262d Mon Sep 17 00:00:00 2001
From: ellson <devnull@localhost>
Date: Tue, 18 Oct 2005 18:27:51 +0000
Subject: [PATCH] don't crash when running dot uninstalled

---
 lib/common/emit.c  | 10 +++++++---
 lib/gvc/gvc.c      |  4 ----
 lib/gvc/gvlayout.c |  3 +++
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/lib/common/emit.c b/lib/common/emit.c
index 24099030b..08681307e 100644
--- a/lib/common/emit.c
+++ b/lib/common/emit.c
@@ -1764,6 +1764,11 @@ int gvRenderJobs (GVC_t * gvc, graph_t * g)
 {
     GVJ_t *job;
 
+    if (!GD_drawing(g)) {
+        fprintf(stderr, "Layout was not done.  Missing layout plugins? \n");
+        return -1;
+    }
+
     init_gvc_from_graph(gvc, g);
     init_layering(gvc, g);
     init_bb(g);
@@ -1771,8 +1776,7 @@ int gvRenderJobs (GVC_t * gvc, graph_t * g)
     gvc->keybindings = gvevent_key_binding;
     gvc->numkeys = gvevent_key_binding_size;
 
-/*     gvc->active_jobs = NULL;  acive job sets can straddle multiple input graphs */
-    for (job = gvrender_first_job(gvc); job; job = gvrender_next_job(gvc)) {
+    for (gvrender_first_job(gvc); job; job = gvrender_next_job(gvc)) {
 	job->g = g;
 
         if (!job->output_file) {        /* if not yet opened */
@@ -1785,7 +1789,7 @@ int gvRenderJobs (GVC_t * gvc, graph_t * g)
         job->output_lang = gvrender_select(job, job->output_langname);
 	if (job->output_lang == NO_SUPPORT) {
 	    fprintf(stderr,"renderer for %s is unavailable\n", job->output_langname);
-	    return 1;
+	    return -1;
 	}
 
         
diff --git a/lib/gvc/gvc.c b/lib/gvc/gvc.c
index 94aa0cf3a..26615b8b6 100644
--- a/lib/gvc/gvc.c
+++ b/lib/gvc/gvc.c
@@ -89,10 +89,6 @@ int gvRender(GVC_t *gvc, graph_t *g, char *format, FILE *out)
 
     job = gvc->job;
     job->output_lang = gvrender_select(job, job->output_langname);
-    if (!GD_drawing(g) && job->output_lang != CANONICAL_DOT) {
-        fprintf(stderr, "Layout was not done\n");
-        return -1;
-    }
     job->output_file = out;
 
     gvRenderJobs(gvc, g);
diff --git a/lib/gvc/gvlayout.c b/lib/gvc/gvlayout.c
index 02e318b92..07bff434c 100644
--- a/lib/gvc/gvlayout.c
+++ b/lib/gvc/gvlayout.c
@@ -60,6 +60,9 @@ int gvLayoutJobs(GVC_t * gvc, graph_t * g)
 {
     gvlayout_engine_t *gvle = gvc->layout.engine;
 
+    if (! gvle)
+	return -1;
+
     graph_init(g, gvc->layout.features->flags & LAYOUT_USES_RANKDIR);
     GD_gvc(g) = gvc;
     if (gvle && gvle->layout)
-- 
2.40.0