GhostPDF - improve warnings when dealing with XObjects

Test file Bug688485.pdf

If a SMask is missing the Group (/G) raise an error rather than
a dmprintf.

Same for a missing or unrecognised Subtype (/S)

And for XObjects with the /PS (PostScript) subtype.

Errors and warnings are preferred to printf because we only report them
once at the end rather than on each occurrence which can be annoyingly
verbose.

1 files changed, 7 insertions, 1 deletions

diff --git a/pdf/pdf_trans.c b/pdf/pdf_trans.c
index ab610ff3c..f04163dd6 100644
--- a/pdf/pdf_trans.c
+++ b/pdf/pdf_trans.c
@@ -144,7 +144,11 @@ static int pdfi_trans_set_mask(pdf_context *ctx, pdfi_int_gstate *igs, int color
         if (code <= 0) {
             dmprintf(ctx->memory, "WARNING: Missing 'G' in SMask, ignoring.\n");
             pdfi_trans_end_smask_notify(ctx);
-            code = 0;
+            if (ctx->args.pdfstoponerror)
+                code = gs_note_error(gs_error_undefined);
+            else
+                code = 0;
+            pdfi_set_error(ctx, 0, NULL, E_PDF_SMASK_MISSING_G, "pdfi_trans_set_mask", "");
             goto exit;
         }
 
@@ -157,6 +161,7 @@ static int pdfi_trans_set_mask(pdf_context *ctx, pdfi_int_gstate *igs, int color
         if (code <= 0) {
             dmprintf(ctx->memory, "WARNING: Missing 'S' in SMask (defaulting to Luminosity)\n");
             subtype = TRANSPARENCY_MASK_Luminosity;
+            pdfi_set_warning(ctx, 0, NULL, W_PDF_SMASK_MISSING_S, "pdfi_trans_set_mask", "");
         }
         else if (pdfi_name_is(S, "Luminosity")) {
             subtype = TRANSPARENCY_MASK_Luminosity;
@@ -165,6 +170,7 @@ static int pdfi_trans_set_mask(pdf_context *ctx, pdfi_int_gstate *igs, int color
         } else {
             dmprintf(ctx->memory, "WARNING: Unknown subtype 'S' in SMask (defaulting to Luminosity)\n");
             subtype = TRANSPARENCY_MASK_Luminosity;
+            pdfi_set_warning(ctx, 0, NULL, W_PDF_SMASK_UNKNOWN_S, "pdfi_trans_set_mask", "");
         }
 
         /* TR is transfer function (Optional) */