fix(interpreter): treat assoc array subscripts as literal strings

crates/bashkit/src/interpreter/mod.rs

@@ -7752,19 +7752,21 @@ impl Interpreter {
         result
     }
 
-    /// Expand a variable by name, checking local scope, positional params, shell vars, then env
     /// Expand a string as a variable reference, or return as literal.
     /// Used for associative array keys which may be variable refs or literals.
+    ///
+    /// In real bash, associative array subscripts are treated as literal strings
+    /// unless they contain explicit `$var` or `${var}` references. A bare name
+    /// like `key` in `${assoc[key]}` is the string "key", NOT the value of
+    /// variable `$key`. (Issue #861)
     fn expand_variable_or_literal(&self, s: &str) -> String {
         // Handle $var and ${var} references in assoc array keys
         let trimmed = s.trim();
         if let Some(var_name) = trimmed.strip_prefix('$') {
             let var_name = var_name.trim_start_matches('{').trim_end_matches('}');
             return self.expand_variable(var_name);
         }
-        if let Some(val) = self.variables.get(s) {
-            return val.clone();
-        }
+        // Bare names are literal string keys — do NOT look up as variables.
         s.to_string()
     }
 

crates/bashkit/tests/spec_cases/bash/assoc-arrays.test.sh

@@ -132,6 +132,47 @@ echo "${m[key]}"
 hello world
 ### end
 
+### assoc_literal_key_not_variable
+# Issue #861: subscripts should be literal strings, not variable lookups
+x="outside"
+declare -A map=([x]=found [outside]=wrong)
+echo "${map[x]}"
+### expect
+found
+### end
+
+### assoc_literal_key_numeric_variable
+i=999
+declare -A assoc=([i]=correct [999]=incorrect)
+echo "${assoc[i]}"
+### expect
+correct
+### end
+
+### assoc_assignment_literal_key
+x="other"
+declare -A m6
+m6[x]="at-x"
+m6[other]="at-other"
+echo "${m6[x]} ${m6[other]}"
+### expect
+at-x at-other
+### end
+
+### assoc_loop_key_variable_does_not_interfere
+a="wrong_a"
+b="wrong_b"
+c="wrong_c"
+declare -A data=([a]=1 [b]=2 [c]=3)
+for k in "${!data[@]}"; do
+  echo "${k}=${data[$k]}"
+done | sort
+### expect
+a=1
+b=2
+c=3
+### end
+
 ### assoc_iteration
 declare -A m
 m[a]="1"