Forms: avoid javascript action execution when engine not available

This was necessary to avoid indirecting through a NULL pointer returned
from pdf_js_get_event, but is a generally sensible restriction.

Also separate the execution of the document-level javascript actions
from the pdf_js contstructor, so that doc->js is set during those
actions.

Also add a missing const

6 files changed, 36 insertions, 15 deletions

diff --git a/pdf/mupdf-internal.h b/pdf/mupdf-internal.h
index fe1bf0ad..ec44a2f4 100644
--- a/pdf/mupdf-internal.h
+++ b/pdf/mupdf-internal.h
@@ -633,6 +633,7 @@ typedef struct pdf_js_event_s
 
 pdf_js *pdf_new_js(pdf_document *doc);
 void pdf_drop_js(pdf_js *js);
+void pdf_js_load_document_level(pdf_js *js);
 void pdf_js_setup_event(pdf_js *js, pdf_js_event *e);
 pdf_js_event *pdf_js_get_event(pdf_js *js);
 void pdf_js_execute(pdf_js *js, char *code);
diff --git a/pdf/pdf_form.c b/pdf/pdf_form.c
index 18b45631..cb92956f 100644
--- a/pdf/pdf_form.c
+++ b/pdf/pdf_form.c
@@ -1558,7 +1558,7 @@ void pdf_update_appearance(pdf_document *doc, pdf_obj *obj)
 			case FZ_WIDGET_TYPE_TEXT:
 				{
 					pdf_obj *formatting = pdf_dict_getp(obj, "AA/F");
-					if (formatting)
+					if (formatting && doc->js)
 					{
 						/* Apply formatting */
 						pdf_js_event e;
@@ -1863,7 +1863,7 @@ static void recalculate(pdf_document *doc)
 	{
 		pdf_obj *co = pdf_dict_getp(doc->trailer, "Root/AcroForm/CO");
 
-		if (co)
+		if (co && doc->js)
 		{
 			int i, n = pdf_array_len(co);
 
@@ -1902,7 +1902,7 @@ int pdf_field_setValue(pdf_document *doc, pdf_obj *field, char *text)
 {
 	pdf_obj *v = pdf_dict_getp(field, "AA/V");
 
-	if (v)
+	if (v && doc->js)
 	{
 		pdf_js_event e;
 
@@ -2116,7 +2116,7 @@ static int run_keystroke(pdf_document *doc, pdf_obj *field, char **text)
 {
 	pdf_obj *k = pdf_dict_getp(field, "AA/K");
 
-	if (k)
+	if (k && doc->js)
 	{
 		pdf_js_event e;
 
diff --git a/pdf/pdf_js.c b/pdf/pdf_js.c
index dd801db7..0059ca4f 100644
--- a/pdf/pdf_js.c
+++ b/pdf/pdf_js.c
@@ -244,7 +244,7 @@ static char *utf8_to_pdf(fz_context *ctx, char *utf8)
 {
 	char *pdf = fz_malloc(ctx, strlen(utf8)+1);
 	int i = 0;
-	char c;
+	unsigned char c;
 
 	while ((c = *utf8) != 0)
 	{
@@ -374,16 +374,12 @@ pdf_js *pdf_new_js(pdf_document *doc)
 {
 	fz_context *ctx = doc->ctx;
 	pdf_js     *js = NULL;
-	pdf_obj    *javascript = NULL;
-	char *codebuf = NULL;
 
 	fz_var(js);
-	fz_var(javascript);
-	fz_var(codebuf);
 	fz_try(ctx)
 	{
-		int len, i;
 		pdf_obj *root, *acroform;
+
 		js = fz_malloc_struct(ctx, pdf_js);
 		js->doc = doc;
 
@@ -399,6 +395,28 @@ pdf_js *pdf_new_js(pdf_document *doc)
 		declare_dom(js);
 
 		preload_helpers(js);
+	}
+	fz_catch(ctx)
+	{
+		pdf_drop_js(js);
+		js = NULL;
+	}
+
+	return js;
+}
+
+void pdf_js_load_document_level(pdf_js *js)
+{
+	pdf_document *doc = js->doc;
+	fz_context *ctx = doc->ctx;
+	pdf_obj    *javascript = NULL;
+	char *codebuf = NULL;
+
+	fz_var(javascript);
+	fz_var(codebuf);
+	fz_try(ctx)
+	{
+		int len, i;
 
 		javascript = pdf_load_name_tree(doc, "JavaScript");
 		len = pdf_dict_len(javascript);
@@ -431,11 +449,8 @@ pdf_js *pdf_new_js(pdf_document *doc)
 	}
 	fz_catch(ctx)
 	{
-		pdf_drop_js(js);
-		js = NULL;
+		fz_rethrow(ctx);
 	}
-
-	return js;
 }
 
 void pdf_drop_js(pdf_js *js)
diff --git a/pdf/pdf_js_none.c b/pdf/pdf_js_none.c
index 6632db5b..310f1a81 100644
--- a/pdf/pdf_js_none.c
+++ b/pdf/pdf_js_none.c
@@ -27,6 +27,10 @@ pdf_js *pdf_new_js(pdf_document *doc)
 	return js;
 }
 
+void pdf_js_load_document_level(pdf_js *js)
+{
+}
+
 void pdf_drop_js(pdf_js *js)
 {
 	if (js)
diff --git a/pdf/pdf_jsimp_cpp.c b/pdf/pdf_jsimp_cpp.c
index aa9539cf..b1767700 100644
--- a/pdf/pdf_jsimp_cpp.c
+++ b/pdf/pdf_jsimp_cpp.c
@@ -106,7 +106,7 @@ char *pdf_jsimp_toString(pdf_jsimp *imp, pdf_jsimp_obj *obj)
 pdf_jsimp_obj *pdf_jsimp_fromNumber(pdf_jsimp *imp, double num)
 {
 	pdf_jsimp_obj *obj = NULL;
-	char *err = pdf_jsimp_fromNumber_cpp(imp, num, &obj);
+	const char *err = pdf_jsimp_fromNumber_cpp(imp, num, &obj);
 	if (err != NULL)
 		fz_throw(pdf_jsimp_ctx_cpp(imp), "%s", err);
 
diff --git a/pdf/pdf_xref.c b/pdf/pdf_xref.c
index 7c14265d..a8b8ab43 100644
--- a/pdf/pdf_xref.c
+++ b/pdf/pdf_xref.c
@@ -782,6 +782,7 @@ pdf_init_document(pdf_document *xref)
 			}
 		}
 		xref->js = pdf_new_js(xref);
+		pdf_js_load_document_level(xref->js);
 	}
 	fz_catch(ctx)
 	{