Show appropriate warning if non-existent export ID is specified

Fixed bug:
  - https://bugs.launchpad.net/inkscape/+bug/1739497

5 files changed, 22 insertions, 1 deletions

diff --git a/src/extension/internal/cairo-ps-out.cpp b/src/extension/internal/cairo-ps-out.cpp
index e8f47e79e..57169ed45 100644
--- a/src/extension/internal/cairo-ps-out.cpp
+++ b/src/extension/internal/cairo-ps-out.cpp
@@ -76,6 +76,9 @@ ps_print_document_to_file(SPDocument *doc, gchar const *filename, unsigned int l
     if (exportId && strcmp(exportId, "")) {
         // we want to export the given item only
         base = SP_ITEM(doc->getObjectById(exportId));
+        if (!base) {
+            throw Inkscape::Extension::Output::export_id_not_found(exportId);
+        }
         pageBoundingBox = exportCanvas;
     }
     else {
diff --git a/src/extension/internal/cairo-renderer-pdf-out.cpp b/src/extension/internal/cairo-renderer-pdf-out.cpp
index 5576676b2..865de1a07 100644
--- a/src/extension/internal/cairo-renderer-pdf-out.cpp
+++ b/src/extension/internal/cairo-renderer-pdf-out.cpp
@@ -71,6 +71,9 @@ pdf_render_document_to_file(SPDocument *doc, gchar const *filename, unsigned int
     if (exportId && strcmp(exportId, "")) {
         // we want to export the given item only
         base = SP_ITEM(doc->getObjectById(exportId));
+        if (!base) {
+            throw Inkscape::Extension::Output::export_id_not_found(exportId);
+        }
         pageBoundingBox = exportCanvas;
     }
     else {
diff --git a/src/extension/internal/latex-text-renderer.cpp b/src/extension/internal/latex-text-renderer.cpp
index 7a1cacbf2..960aec7a9 100644
--- a/src/extension/internal/latex-text-renderer.cpp
+++ b/src/extension/internal/latex-text-renderer.cpp
@@ -41,6 +41,7 @@
 
 #include "util/units.h"
 
+#include "extension/output.h"
 #include "extension/system.h"
 
 #include "inkscape-version.h"
@@ -68,7 +69,9 @@ latex_render_document_text_to_file( SPDocument *doc, gchar const *filename,
     if (exportId && strcmp(exportId, "")) {
         // we want to export the given item only
         base = dynamic_cast<SPItem *>(doc->getObjectById(exportId));
-        g_assert(base != NULL);
+        if (!base) {
+            throw Inkscape::Extension::Output::export_id_not_found(exportId);
+        }
         pageBoundingBox = exportCanvas;
     }
     else {
diff --git a/src/extension/output.h b/src/extension/output.h
index 44a731ca0..420eb9245 100644
--- a/src/extension/output.h
+++ b/src/extension/output.h
@@ -31,6 +31,11 @@ public:
     class save_cancelled {};     /**< Saving was cancelled */
     class no_extension_found {}; /**< Failed because we couldn't find an extension to match the filename */
     class file_read_only {};     /**< The existing file can not be opened for writing */
+    class export_id_not_found {  /**< The object ID requested for export could not be found in the document */
+        public:
+            const gchar * const id;
+            export_id_not_found(const gchar * const id = NULL) : id{id} {};
+    };
 
                  Output (Inkscape::XML::Node * in_repr,
                          Implementation::Implementation * in_imp);
diff --git a/src/file.cpp b/src/file.cpp
index e5caaaca0..9cf0448e1 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -658,6 +658,13 @@ file_save(Gtk::Window &parentWindow, SPDocument *doc, const Glib::ustring &uri,
         SP_ACTIVE_DESKTOP->messageStack()->flash(Inkscape::ERROR_MESSAGE, _("Document not saved."));
         doc->getReprRoot()->setAttribute("inkscape:version", sp_version_to_string( save ));
         return false;
+    } catch (Inkscape::Extension::Output::export_id_not_found &e) {
+        gchar *text = g_strdup_printf(_("File could not be saved:\nNo object with ID '%s' found."), e.id);
+        SP_ACTIVE_DESKTOP->messageStack()->flash(Inkscape::ERROR_MESSAGE, _("Document not saved."));
+        sp_ui_error_dialog(text);
+        g_free(text);
+        doc->getReprRoot()->setAttribute("inkscape:version", sp_version_to_string( save ));
+        return false;
     } catch (Inkscape::Extension::Output::no_overwrite &e) {
         return sp_file_save_dialog(parentWindow, doc, save_method);
     } catch (...) {