[librsvg/wip/rust-api: 8/11] rsvg_error_quark(): Port to Rust

[Federico Mena Quintero <federico src gnome org>]

commit 4357053826708314352d2aa07bfdf28a68fff70b
Author: Federico Mena Quintero <federico gnome org>
Date:   Wed Feb 13 18:32:10 2019 -0600

    rsvg_error_quark(): Port to Rust
    
    This lets us avoid calling into C to get the error quark from Rust.

 librsvg/rsvg-base.c         |  7 ++++---
 librsvg_crate/src/lib.rs    |  4 +++-
 rsvg_internals/src/error.rs | 13 +++++++------
 rsvg_internals/src/lib.rs   |  2 +-
 4 files changed, 15 insertions(+), 11 deletions(-)
---
diff --git a/librsvg/rsvg-base.c b/librsvg/rsvg-base.c
index 1afb1582..380176af 100644
--- a/librsvg/rsvg-base.c
+++ b/librsvg/rsvg-base.c
@@ -31,6 +31,9 @@
 /* Implemented in rsvg_internals/src/dpi.rs */
 extern void rsvg_rust_set_default_dpi_x_y(double dpi_x, double dpi_y);
 
+/* Implemented in rsvg_internals/src/error.rs */
+extern GQuark rsvg_rust_error_quark (void);
+
 /**
  * rsvg_error_quark:
  *
@@ -41,9 +44,7 @@ extern void rsvg_rust_set_default_dpi_x_y(double dpi_x, double dpi_y);
 GQuark
 rsvg_error_quark (void)
 {
-    /* don't use from_static_string(), since librsvg might be used in a module
-       that's ultimately unloaded */
-    return g_quark_from_string ("rsvg-error-quark");
+    return rsvg_rust_error_quark ();
 }
 
 /**
diff --git a/librsvg_crate/src/lib.rs b/librsvg_crate/src/lib.rs
index 48f6e8d4..e680c19f 100644
--- a/librsvg_crate/src/lib.rs
+++ b/librsvg_crate/src/lib.rs
@@ -115,7 +115,9 @@ impl<'a> CairoRenderer<'a> {
     }
 
     pub fn get_dimensions(&self) -> Result<(i32, i32), RenderingError> {
-        self.handle.0.get_dimensions()
+        self.handle
+            .0
+            .get_dimensions()
             .map(|dimensions| (dimensions.width, dimensions.height))
     }
 
diff --git a/rsvg_internals/src/error.rs b/rsvg_internals/src/error.rs
index a9ef26f5..48c86db8 100644
--- a/rsvg_internals/src/error.rs
+++ b/rsvg_internals/src/error.rs
@@ -277,10 +277,6 @@ impl From<glib::Error> for LoadingError {
     }
 }
 
-extern "C" {
-    fn rsvg_error_quark() -> glib_sys::GQuark;
-}
-
 pub fn set_gerror(err: *mut *mut glib_sys::GError, code: u32, msg: &str) {
     unsafe {
         // this is RSVG_ERROR_FAILED, the only error code available in RsvgError
@@ -288,7 +284,7 @@ pub fn set_gerror(err: *mut *mut glib_sys::GError, code: u32, msg: &str) {
 
         glib_sys::g_set_error_literal(
             err,
-            rsvg_error_quark(),
+            rsvg_rust_error_quark(),
             code as libc::c_int,
             msg.to_glib_none().0,
         );
@@ -325,7 +321,7 @@ pub const RSVG_ERROR_FAILED: i32 = 0;
 
 impl ErrorDomain for RsvgError {
     fn domain() -> glib::Quark {
-        from_glib(unsafe { rsvg_error_quark() })
+        glib::Quark::from_string("rsvg-error-quark")
     }
 
     fn code(self) -> i32 {
@@ -339,3 +335,8 @@ impl ErrorDomain for RsvgError {
         }
     }
 }
+
+#[no_mangle]
+pub extern "C" fn rsvg_rust_error_quark() -> glib_sys::GQuark {
+    RsvgError::domain().to_glib()
+}
diff --git a/rsvg_internals/src/lib.rs b/rsvg_internals/src/lib.rs
index b6dbac2c..704421af 100644
--- a/rsvg_internals/src/lib.rs
+++ b/rsvg_internals/src/lib.rs
@@ -44,7 +44,7 @@ pub use color::{rsvg_css_parse_color, ColorKind, ColorSpec};
 
 pub use dpi::{rsvg_rust_set_default_dpi_x_y, Dpi};
 
-pub use error::{LoadingError, RenderingError};
+pub use error::{rsvg_rust_error_quark, LoadingError, RenderingError};
 
 pub use handle::{
     rsvg_handle_rust_close,