Batch fix: EPS: filter keeps its source, so an image's data source isn't skipped twice (#1909)

crates/pdf/src/ps.rs

@@ -1271,31 +1271,33 @@ impl Interp {
             }
             // `source [params] /Name filter`. A SubFileDecode of the current file with a count of
             // 0 reads to its end-of-data string: skip that data (an embedded XMP packet, which
-            // otherwise ran as PostScript). Other filters stand for the file they read.
+            // otherwise ran as PostScript). Other filters read what their source reads.
             "filter" => {
                 let name = self.pop().key();
-                if name == "SubFileDecode" {
+                let mut skipped = false;
+                let source = if name == "SubFileDecode" && !matches!(self.st.last(), Some(V::Dict(_))) {
                     let eod = match self.pop() {
                         V::Str(s) => s.borrow().clone(),
                         _ => vec![],
                     };
                     let count = self.popn();
-                    if let V::File = self.pop()
-                        && count == 0.0
-                        && !eod.is_empty()
-                    {
+                    let source = self.pop();
+                    if matches!(source, V::File) && count == 0.0 && !eod.is_empty() {
                         src.pos = match find_from(src.d, &eod, src.pos) {
                             Some(p) => p.saturating_add(eod.len()),
                             None => src.d.len(),
                         };
+                        skipped = true;
                     }
+                    source
                 } else {
                     if matches!(self.st.last(), Some(V::Dict(_))) {
                         self.pop();
                     }
-                    self.pop();
-                }
-                self.push(V::File);
+                    self.pop()
+                };
+                // Data already stepped over leaves nothing for `image` to skip.
+                self.push(if skipped { V::Null } else { source });
             }
             "vmstatus" => {
                 for _ in 0..3 {

crates/pdf/src/tests_import.rs

@@ -45,6 +45,16 @@ fn eps_with_aliased_operators_device_queries_and_embedded_data_draws() {
     assert!(coverage(&render(&doc), 50, 25, 150, 75) > 4900.0, "drawing after the embedded data");
 }
 
+#[test]
+fn eps_filter_on_a_string_source_does_not_skip_the_program() {
+    let square = "1 0 0 setrgbcolor 50 25 moveto 150 25 lineto 150 75 lineto 50 75 lineto closepath fill\n";
+    let img = "gsave 1 1 8 [1 0 0 1 0 0] (FF) /ASCIIHexDecode filter image grestore\n";
+    // Images aren't drawn yet, so this parses without `eps`'s nothing-skipped check.
+    let doc = parse(format!("%!PS-Adobe-3.0 EPSF-3.0\n%%BoundingBox: 0 0 200 100\n{img}{square}").as_bytes()).unwrap();
+    assert_eq!(doc.skipped, ["image"]);
+    assert!(coverage(&render(&doc), 50, 25, 150, 75) > 4900.0, "drawing after an image read from a string");
+}
+
 #[test]
 fn eps_text_with_bundled_fonts_and_show_variants() {
     // Not embedded: drawn with the bundled stand-in, like the same text in a PDF.