Merge pull request #16 from storytold/pr/never-crash-pdf

Never crash: PDF/EPS close-path, CFF outlines and PostScript radix numbers

crates/pdf/src/cff.rs

@@ -646,12 +646,21 @@ impl T2<'_> {
         self.path.move_to((self.x, self.y));
         self.open = true;
     }
+    /// A segment before the first moveto starts at the current point.
+    fn ensure_open(&mut self) {
+        if !self.open {
+            self.path.move_to((self.x, self.y));
+            self.open = true;
+        }
+    }
     fn line_to(&mut self, dx: f64, dy: f64) {
+        self.ensure_open();
         self.x += dx;
         self.y += dy;
         self.path.line_to((self.x, self.y));
     }
     fn curve(&mut self, d: [f64; 6]) {
+        self.ensure_open();
         let (x1, y1) = (self.x + d[0], self.y + d[1]);
         let (x2, y2) = (x1 + d[2], y1 + d[3]);
         self.x = x2 + d[4];

crates/pdf/src/lib.rs

@@ -7,6 +7,8 @@
 //! children are the document's **layers**: one group per top-level optional-content group
 //! (Illustrator layers), with content outside them gathered into groups of its own.
 
+#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
+
 mod build;
 mod ccitt;
 mod cff;

crates/pdf/src/page.rs

@@ -332,7 +332,7 @@ impl<'a> Interp<'a> {
                 // Painting.
                 "S" => self.paint(false, None, true, depth),
                 "s" => {
-                    self.path.close_path();
+                    self.close_subpath();
                     self.paint(false, None, true, depth)
                 }
                 "f" | "F" => self.paint(true, Some(FillRule::NonZero), false, depth),
@@ -340,11 +340,11 @@ impl<'a> Interp<'a> {
                 "B" => self.paint(true, Some(FillRule::NonZero), true, depth),
                 "B*" => self.paint(true, Some(FillRule::EvenOdd), true, depth),
                 "b" => {
-                    self.path.close_path();
+                    self.close_subpath();
                     self.paint(true, Some(FillRule::NonZero), true, depth)
                 }
                 "b*" => {
-                    self.path.close_path();
+                    self.close_subpath();
                     self.paint(true, Some(FillRule::EvenOdd), true, depth)
                 }
                 "n" => self.paint(false, None, false, depth),
@@ -549,6 +549,13 @@ impl<'a> Interp<'a> {
         }
     }
 
+    /// Close the current subpath; nothing to close without a current point.
+    fn close_subpath(&mut self) {
+        if self.cur.is_some() {
+            self.path.close_path();
+        }
+    }
+
     fn ensure_start(&mut self) {
         if self.cur.is_none() {
             self.path.move_to((0.0, 0.0));

crates/pdf/src/ps.rs

@@ -278,7 +278,7 @@ impl Src<'_> {
                     None => {
                         // Radix numbers (16#FF).
                         let s = String::from_utf8_lossy(w).into_owned();
-                        match s.split_once('#').and_then(|(r, v)| i64::from_str_radix(v, r.parse().ok()?).ok()) {
+                        match s.split_once('#').and_then(|(r, v)| i64::from_str_radix(v, r.parse::<u32>().ok().filter(|r| (2..=36).contains(r))?).ok()) {
                             Some(n) => V::Num(n as f64),
                             None => V::Name(s.into()),
                         }

crates/pdf/src/tests_import.rs

@@ -295,3 +295,21 @@ fn truncated_and_corrupt_eps_never_panic() {
         assert!(r.is_ok(), "{}", String::from_utf8_lossy(prog));
     }
 }
+
+#[test]
+fn closing_an_empty_path_is_a_no_op() {
+    // "s", "b" and "b*" closed the path without a current point (kurbo asserts on that).
+    for ops in ["s", "b", "b*", "0 0 m 50 0 l 50 50 l b s b*", "f s 10 10 m 20 20 l s"] {
+        let doc = parse(&page_pdf(ops, "", vec![])).unwrap();
+        let _ = render(&doc);
+    }
+}
+
+#[test]
+fn postscript_radix_numbers_outside_2_to_36_are_not_numbers() {
+    // `0#7` asked `i64::from_str_radix` for radix 0, which panics (found by fuzzing).
+    for n in ["0#7", "1#1", "37#1", "99999999999#1", "16#FF"] {
+        let src = format!("%!PS-Adobe-3.0 EPSF-3.0\n%%BoundingBox: 0 0 100 100\n{n} pop 0 0 moveto 10 10 lineto stroke\n");
+        let _ = parse(src.as_bytes());
+    }
+}