fix(wasi) Allow the = sign in the environment variable value.

CHANGELOG.md

@@ -20,6 +20,10 @@
 - [#1709](https://github.com/wasmerio/wasmer/pull/1709) Implement `wasm_module_name` and `wasm_module_set_name` in the Wasm(er) C API.
 - [#1700](https://github.com/wasmerio/wasmer/pull/1700) Implement `wasm_externtype_copy` in the Wasm C API.
 
+### Changed
+
+- [#1762](https://github.com/wasmerio/wasmer/pull/1762) Allow the `=` sign in a WASI environment variable value.
+
 ### Fixed
 
 - [#1718](https://github.com/wasmerio/wasmer/pull/1718) Fix panic in the API in some situations when the memory's min bound was greater than the memory's max bound.

lib/wasi/src/state/builder.rs

@@ -328,33 +328,15 @@ impl WasiStateBuilder {
                 }
             }
         }
+
         for env in self.envs.iter() {
-            let mut eq_seen = false;
-            for b in env.iter() {
-                match *b {
-                    b'=' => {
-                        if eq_seen {
-                            return Err(WasiStateCreationError::EnvironmentVariableFormatError(
-                                format!(
-                                    "found '=' in env var string \"{}\" (key=value)",
-                                    std::str::from_utf8(env)
-                                        .unwrap_or("Inner error: env var is invalid_utf8!")
-                                ),
-                            ));
-                        }
-                        eq_seen = true;
-                    }
-                    0 => {
-                        return Err(WasiStateCreationError::EnvironmentVariableFormatError(
-                            format!(
-                                "found nul byte in env var string \"{}\" (key=value)",
-                                std::str::from_utf8(env)
-                                    .unwrap_or("Inner error: env var is invalid_utf8!")
-                            ),
-                        ));
-                    }
-                    _ => (),
-                }
+            if env.iter().find(|&&ch| ch == 0).is_some() {
+                return Err(WasiStateCreationError::EnvironmentVariableFormatError(
+                    format!(
+                        "found nul byte in env var string \"{}\" (key=value)",
+                        std::str::from_utf8(env).unwrap_or("Inner error: env var is invalid_utf8!")
+                    ),
+                ));
             }
         }
 
@@ -508,17 +490,21 @@ mod test {
 
     #[test]
     fn env_var_errors() {
+        // `a=b` means key is `a` and value is `b`, which is OK.
+        // `a=b=c` means key is `a` and value is `b=c`, which is OK too.
         let output = create_wasi_state("test_prog")
-            .env("HOM=E", "/home/home")
+            .env("HOME", "/home/home=foo")
             .build();
+
         match output {
-            Err(WasiStateCreationError::EnvironmentVariableFormatError(_)) => assert!(true),
-            _ => assert!(false),
+            Err(WasiStateCreationError::EnvironmentVariableFormatError(_)) => assert!(false),
+            _ => assert!(true),
         }
 
         let output = create_wasi_state("test_prog")
             .env("HOME\0", "/home/home")
             .build();
+
         match output {
             Err(WasiStateCreationError::EnvironmentVariableFormatError(_)) => assert!(true),
             _ => assert!(false),