Fix malloc errors!

flake.nix

@@ -3,16 +3,21 @@
     nixpkgs.url = "github:nixos/nixpkgs";
   };
 
-  outputs = { self, nixpkgs }: let
+  outputs = {
+    self,
+    nixpkgs,
+  }: let
     inherit (nixpkgs) lib;
     systems = ["x86_64-linux"];
-    eachSystem = f: lib.genAttrs systems (system: f {
-      inherit system;
-      pkgs = nixpkgs.legacyPackages.${system};
-      ownPkgs = self.packages.${system};
-    });
+    eachSystem = f:
+      lib.genAttrs systems (system:
+        f {
+          inherit system;
+          pkgs = nixpkgs.legacyPackages.${system};
+          ownPkgs = self.packages.${system};
+        });
   in {
-    packages = eachSystem ({ pkgs, ... }: {
+    packages = eachSystem ({pkgs, ...}: {
       default = pkgs.rustPlatform.buildRustPackage (final: {
         pname = "zathura-typst";
         version = "0.1.0";
@@ -48,10 +53,22 @@
       });
     });
 
-    devShells = eachSystem ({ pkgs, ownPkgs, ... }: {
+    devShells = eachSystem ({
+      pkgs,
+      ownPkgs,
+      ...
+    }: {
       default = pkgs.mkShell {
         inputsFrom = [ownPkgs.default];
-        packages = [pkgs.rust-analyzer pkgs.clippy pkgs.rustfmt pkgs.gdb];
+        packages = [
+          pkgs.rust-analyzer
+          pkgs.clippy
+          pkgs.rustfmt
+          pkgs.gdb
+          (pkgs.zathuraPkgs.zathura_core.overrideAttrs {
+            mesonBuildType = "debug";
+          })
+        ];
         LIBCLANG_PATH = "${pkgs.llvmPackages.libclang.lib}/lib";
         shellHook = ''
           # From: https://github.com/NixOS/nixpkgs/blob/1fab95f5190d087e66a3502481e34e15d62090aa/pkgs/applications/networking/browsers/firefox/common.nix#L247-L253

src/lib.rs

@@ -1,6 +1,6 @@
 use std::{
     cmp::{max, min},
-    ffi::{CStr, CString, OsStr, c_void},
+    ffi::{CStr, OsStr, c_void},
     fs,
     os::unix::ffi::OsStrExt,
     path::Path,
@@ -41,6 +41,17 @@ mod typst;
 mod zathura;
 use typst::TypstDocument;
 
+unsafe extern "C" {
+    safe fn calloc(n: usize, s: usize) -> *mut c_void;
+}
+
+fn alloc_c_string(bytes: &[u8]) -> *mut i8 {
+    let cstr = calloc(bytes.len() + 1, 1);
+    unsafe { slice::from_raw_parts_mut(cstr as *mut u8, bytes.len()) }
+        .copy_from_slice(bytes);
+    cstr as *mut i8
+}
+
 #[allow(non_upper_case_globals)]
 #[unsafe(no_mangle)]
 pub static zathura_plugin_6_7: zathura::zathura_plugin_definition_s =
@@ -151,15 +162,7 @@ unsafe extern "C" fn document_get_information(
     ]
     .into_iter()
     .filter(|(_, st)| !st.is_empty())
-    .map(|(ty, st)| {
-        unsafe extern "C" {
-            safe fn calloc(n: usize, s: usize) -> *mut c_void;
-        }
-        let st_m = calloc(st.len() + 1, 1);
-        unsafe { slice::from_raw_parts_mut(st_m as *mut u8, st.len()) }
-            .copy_from_slice(st.as_bytes());
-        (ty, st_m as *const i8)
-    })
+    .map(|(ty, st)| (ty, alloc_c_string(st.as_bytes())))
     .for_each(|(ty, st)| {
         unsafe { lst.append_allocated(zathura_document_information_entry_new(ty, st)) };
     });
@@ -447,13 +450,7 @@ unsafe extern "C" fn page_links_get(
                     zathura_link_target_s {
                         destination_type:
                             zathura_link_destination_type_e_ZATHURA_LINK_DESTINATION_UNKNOWN,
-                        value: doc
-                            .cstring_cache
-                            .entry(url.to_string())
-                            .or_insert_with(|| {
-                                CString::new(url.as_bytes()).expect("URL shouldn't contain NUL")
-                            })
-                            .as_ptr() as *mut i8,
+                        value: alloc_c_string(url.as_bytes()),
                         page_number: 0,
                         left: -1.,
                         right: -1.,
@@ -506,13 +503,10 @@ unsafe extern "C" fn page_links_get(
 }
 
 unsafe extern "C" fn page_get_label(
-    zpage: *mut zathura_page_t,
+    _zpage: *mut zathura_page_t,
     page: *mut c_void,
     out: *mut *mut i8,
 ) -> ZathuraResult {
-    let doc = unsafe {
-        &mut *(zathura_document_get_data(zathura_page_get_document(zpage)) as *mut TypstDocument)
-    };
     let page = unsafe { &*(page as *mut Page) };
     let numbering = match page.numbering.clone() {
         Some(Numbering::Pattern(numbering)) => numbering,
@@ -520,11 +514,7 @@ unsafe extern "C" fn page_get_label(
     };
 
     let label = numbering.apply(&[page.number]);
-    let label = doc
-        .cstring_cache
-        .entry(label.to_string())
-        .or_insert_with_key(|k| CString::new(k.to_owned()).expect("It's a string"))
-        .as_ptr();
+    let label = alloc_c_string(label.as_bytes());
 
     unsafe { out.write(label as _) };
     ZathuraResult::OK

src/typst.rs

@@ -1,5 +1,5 @@
 use std::{
-    collections::{hash_map::Entry, HashMap}, ffi::CString, hash::Hash, io::{self, ErrorKind}, iter, path::{Path, PathBuf}, slice, sync::{LazyLock, Mutex}
+    collections::{hash_map::Entry, HashMap}, hash::Hash, io::{self, ErrorKind}, iter, path::{Path, PathBuf}, slice, sync::{LazyLock, Mutex}
 };
 
 use codespan_reporting::{
@@ -131,7 +131,6 @@ impl World {
 pub struct TypstDocument {
     pub doc: typst::layout::PagedDocument,
     pub warnings: Vec<SourceDiagnostic>,
-    pub cstring_cache: HashMap<String, CString>,
 }
 
 #[allow(clippy::result_large_err)]
@@ -147,7 +146,6 @@ fn compile(path: &Path) -> Result<TypstDocument, (Option<World>, Vec<SourceDiagn
         Ok(doc) => Ok(TypstDocument {
             doc,
             warnings: warnings.to_vec(),
-            cstring_cache: Default::default(),
         }),
         Err(mut errors) => {
             errors.extend(warnings);
@@ -279,7 +277,6 @@ fn diagnostics(world: &World, errors: impl IntoIterator<Item = SourceDiagnostic>
     TypstDocument {
         doc: output.expect("Should be valid syntax"),
         warnings: vec![],
-        cstring_cache: Default::default()
     }
 }