Fix parsing of INT_MIN %arg

Fixes #4601

5 files changed, 11 insertions, 3 deletions

diff --git a/src/command_manager.cc b/src/command_manager.cc
index b8784093..266b832d 100644
--- a/src/command_manager.cc
+++ b/src/command_manager.cc
@@ -382,10 +382,10 @@ void expand_token(Token&& token, const Context& context, const ShellContext& she
                 return set_target(params);
         }
 
-        const int arg = str_to_int(content)-1;
-        if (arg < 0)
+        const int arg = str_to_int(content);
+        if (arg < 1)
             throw runtime_error("invalid argument index");
-        return set_target(arg < params.size() ? params[arg] : String{});
+        return set_target(arg <= params.size() ? params[arg-1] : String{});
     }
     case Token::Type::FileExpand:
         return set_target(read_file(content));
diff --git a/test/regression/4601-int-min-arg/cmd b/test/regression/4601-int-min-arg/cmd
new file mode 100644
index 00000000..8b137891
--- /dev/null
+++ b/test/regression/4601-int-min-arg/cmd
@@ -0,0 +1 @@
+
diff --git a/test/regression/4601-int-min-arg/in b/test/regression/4601-int-min-arg/in
new file mode 100644
index 00000000..8b137891
--- /dev/null
+++ b/test/regression/4601-int-min-arg/in
@@ -0,0 +1 @@
+
diff --git a/test/regression/4601-int-min-arg/out b/test/regression/4601-int-min-arg/out
new file mode 100644
index 00000000..9766475a
--- /dev/null
+++ b/test/regression/4601-int-min-arg/out
@@ -0,0 +1 @@
+ok
diff --git a/test/regression/4601-int-min-arg/rc b/test/regression/4601-int-min-arg/rc
new file mode 100644
index 00000000..b9a641ac
--- /dev/null
+++ b/test/regression/4601-int-min-arg/rc
@@ -0,0 +1,5 @@
+try %{
+    nop %arg{-2147483648}
+} catch %{
+    exec iok<esc>
+}