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[python] fix crash when manipulating string in internal variable

This fixes the following crash:

(gdb) set $blah = "whatever"
(gdb) set $blah[4] = 0

which was introduced by:

commit b5cdb6e5cfc537b99173fe981e81a87d1ebe4566
Author: Tom Tromey <>
Date:   Fri Oct 17 10:50:26 2008 -0600

The problem is that value_subscripted_rvalue tries to set the address of
an internalvar_component value, which trips a gdb_assert in
set_value_address. The underlying thinko is also present in upstream
GDB, but the code works there because it uses the VALUE_ADDRESS macro
which happens to work.

I won't submit this patch upstream because I'm not sure it's right,
since I don't know much about the implementation of internal variables.

2008-11-23  Thiago Jung Bauermann  <>

	* valarith.c (value_subscripted_rvalue,
	value_bitstring_subscript): Fix internal error when given a value
	for an internal variable.

diff --git a/gdb/valarith.c b/gdb/valarith.c
index 1c114f6..36100c1 100644
--- a/gdb/valarith.c
+++ b/gdb/valarith.c
@@ -234,10 +234,15 @@ value_subscripted_rvalue (struct value *array, struct value *idx, int lowerbound
 	    value_contents (array) + elt_offs, elt_size);
   if (VALUE_LVAL (array) == lval_internalvar)
-    VALUE_LVAL (v) = lval_internalvar_component;
+    {
+      VALUE_LVAL (v) = lval_internalvar_component;
+    }
-    VALUE_LVAL (v) = VALUE_LVAL (array);
-  set_value_address (v, value_raw_address (array));
+    {
+      VALUE_LVAL (v) = VALUE_LVAL (array);
+      set_value_address (v, value_raw_address (array));
+    }
   set_value_offset (v, value_offset (array) + elt_offs);
@@ -280,8 +285,12 @@ value_bitstring_subscript (struct type *type,
   VALUE_LVAL (v) = VALUE_LVAL (bitstring);
   if (VALUE_LVAL (bitstring) == lval_internalvar)
-    VALUE_LVAL (v) = lval_internalvar_component;
-  set_value_address (v, value_raw_address (bitstring));
+    {
+      VALUE_LVAL (v) = lval_internalvar_component;
+    }
+  else
+    set_value_address (v, value_raw_address (bitstring));
   VALUE_FRAME_ID (v) = VALUE_FRAME_ID (bitstring);
   set_value_offset (v, offset + value_offset (bitstring));

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