[librsvg: 18/25] stroke-dash-array: Handle the case where a comma would be followed up with another comma.

[Federico Mena Quintero <federico src gnome org>]

commit fac54f7bb16716fdc11ac039da24d0c4741ebbfd
Author: Jordan Petridis <jordanpetridis protonmail com>
Date:   Wed Jan 31 16:05:21 2018 +0200

    stroke-dash-array: Handle the case where a comma would be followed up with another comma.

 .gitlab-ci.yml     |  4 ++--
 rust/src/length.rs | 21 ++++++++++++---------
 rust/src/lib.rs    |  1 +
 3 files changed, 15 insertions(+), 11 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 1ca612c..e7e53b3 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -24,11 +24,11 @@ test:
     - ./autogen.sh --enable-debug
     - make check
   after_script:
-    - mkdir test_artifacts
+    - mkdir png_artifacts
     - cp /tmp/*.png png_artifacts
 
   artifacts:
     when: on_failure
     paths:
       - tests/*.log
-      - png_artifacts/
+      - png_artifacts
diff --git a/rust/src/length.rs b/rust/src/length.rs
index 0d658c0..d091aa6 100644
--- a/rust/src/length.rs
+++ b/rust/src/length.rs
@@ -2,6 +2,7 @@ use cssparser::{Parser, ParserInput, Token};
 use glib_sys;
 use glib::translate::*;
 use libc;
+use regex::Regex;
 
 use std::f64::consts::*;
 use std::mem;
@@ -342,8 +343,15 @@ fn parse_dash_array(s: &str) -> Result<Vec<RsvgLength>, AttributeError> {
         }
     }
 
+    // TODO: Use lazy static to avoid constructing the regex on each function call.
+    let commas = Regex::new(r",\s*,").unwrap();
+
+    if commas.is_match(s) {
+        return Err(AttributeError::Parse(ParseError::new("expected number, found comma")));
+    }
+
     // Values can be comma or whitespace separated.
-    let dashes = s.split(',') // split at comma
+    s.split(',') // split at comma
         // split at whitespace
         .flat_map(|slice| slice.split_whitespace())
         // parse it into an RsvgLength
@@ -351,14 +359,7 @@ fn parse_dash_array(s: &str) -> Result<Vec<RsvgLength>, AttributeError> {
         // collect into a Result<Vec<T>, E>.
         // it will short-circuit iteslf upon the first error encountered
         // like if you returned from a for-loop
-        .collect::<Result<Vec<_>, _>>()?;
-
-    // This can occure when input is something like ",,,"
-    if dashes.is_empty() {
-        return Err(AttributeError::Parse(ParseError::new("parse error")));
-    }
-
-    Ok(dashes)
+        .collect::<Result<Vec<_>, _>>()
 }
 
 
@@ -599,5 +600,7 @@ mod tests {
         assert!(parse_dash_array(",,,").is_err());
         // No trailling commas allowed, parse error
         assert!(parse_dash_array("10,").is_err());
+        // A comma should be followed by a number
+        assert!(parse_dash_array("20,,10").is_err());
     }
 }
diff --git a/rust/src/lib.rs b/rust/src/lib.rs
index 8c6f1b6..4823049 100644
--- a/rust/src/lib.rs
+++ b/rust/src/lib.rs
@@ -11,6 +11,7 @@ extern crate libc;
 extern crate itertools;
 extern crate pango;
 extern crate pango_sys;
+extern crate regex;
 
 #[macro_use]
 extern crate downcast_rs;