[5/5] Use correct inferior in Inferior.read_memory et al

diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
index af8bd8855a3..7fb422f621e 100644
--- a/gdb/python/py-inferior.c
+++ b/gdb/python/py-inferior.c
@@ -30,6 +30,7 @@ 
 #include "gdbsupport/gdb_signals.h"
 #include "py-event.h"
 #include "py-stopevent.h"
+#include "progspace-and-thread.h"
 #include <unordered_map>
 
 using thread_map_t
@@ -528,11 +529,14 @@  gdbpy_inferiors (PyObject *unused, PyObject *unused2)
 static PyObject *
 infpy_read_memory (PyObject *self, PyObject *args, PyObject *kw)
 {
+  inferior_object *inf = (inferior_object *) self;
   CORE_ADDR addr, length;
   gdb::unique_xmalloc_ptr<gdb_byte> buffer;
   PyObject *addr_obj, *length_obj;
   static const char *keywords[] = { "address", "length", NULL };
 
+  INFPY_REQUIRE_VALID (inf);
+
   if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "OO", keywords,
 					&addr_obj, &length_obj))
     return NULL;
@@ -543,6 +547,12 @@  infpy_read_memory (PyObject *self, PyObject *args, PyObject *kw)
 
   try
     {
+      scoped_restore_current_inferior restore_inferior;
+      scoped_restore_current_pspace_and_thread restore_thread;
+
+      thread_info *thr = any_thread_of_inferior (inf->inferior);
+      switch_to_thread_no_regs (thr);
+
       buffer.reset ((gdb_byte *) xmalloc (length));
 
       read_memory (addr, buffer.get (), length);
@@ -565,6 +575,7 @@  infpy_read_memory (PyObject *self, PyObject *args, PyObject *kw)
 static PyObject *
 infpy_write_memory (PyObject *self, PyObject *args, PyObject *kw)
 {
+  inferior_object *inf = (inferior_object *) self;
   struct gdb_exception except;
   Py_ssize_t buf_len;
   const gdb_byte *buffer;
@@ -573,6 +584,8 @@  infpy_write_memory (PyObject *self, PyObject *args, PyObject *kw)
   static const char *keywords[] = { "address", "buffer", "length", NULL };
   Py_buffer pybuf;
 
+  INFPY_REQUIRE_VALID (inf);
+
   if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "Os*|O", keywords,
 					&addr_obj, &pybuf, &length_obj))
     return NULL;
@@ -591,6 +604,12 @@  infpy_write_memory (PyObject *self, PyObject *args, PyObject *kw)
 
   try
     {
+      scoped_restore_current_inferior restore_inferior;
+      scoped_restore_current_pspace_and_thread restore_thread;
+
+      thread_info *thr = any_thread_of_inferior (inf->inferior);
+      switch_to_thread_no_regs (thr);
+
       write_memory_with_notification (addr, buffer, length);
     }
   catch (gdb_exception &ex)
@@ -604,7 +623,7 @@  infpy_write_memory (PyObject *self, PyObject *args, PyObject *kw)
 }
 
 /* Implementation of
-   gdb.search_memory (address, length, pattern).  ADDRESS is the
+   Inferior.search_memory (address, length, pattern).  ADDRESS is the
    address to start the search.  LENGTH specifies the scope of the
    search from ADDRESS.  PATTERN is the pattern to search for (and
    must be a Python object supporting the buffer protocol).
@@ -614,6 +633,7 @@  infpy_write_memory (PyObject *self, PyObject *args, PyObject *kw)
 static PyObject *
 infpy_search_memory (PyObject *self, PyObject *args, PyObject *kw)
 {
+  inferior_object *inf = (inferior_object *) self;
   struct gdb_exception except;
   CORE_ADDR start_addr, length;
   static const char *keywords[] = { "address", "length", "pattern", NULL };
@@ -624,6 +644,8 @@  infpy_search_memory (PyObject *self, PyObject *args, PyObject *kw)
   int found = 0;
   Py_buffer pybuf;
 
+  INFPY_REQUIRE_VALID (inf);
+
   if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "OOs*", keywords,
 					&start_addr_obj, &length_obj,
 					&pybuf))
@@ -656,6 +678,12 @@  infpy_search_memory (PyObject *self, PyObject *args, PyObject *kw)
 
   try
     {
+      scoped_restore_current_inferior restore_inferior;
+      scoped_restore_current_pspace_and_thread restore_thread;
+
+      thread_info *thr = any_thread_of_inferior (inf->inferior);
+      switch_to_thread_no_regs (thr);
+
       found = target_search_memory (start_addr, length,
 				    buffer, pattern_size,
 				    &found_addr);
@@ -912,10 +940,10 @@  infpy_get_main_name (PyObject *self, void *closure)
       /* This is unfortunate but the implementation of main_name can
 	 reach into memory.  */
       scoped_restore_current_inferior restore_inferior;
-      set_current_inferior (inf->inferior);
+      scoped_restore_current_pspace_and_thread restore_thread;
 
-      scoped_restore_current_program_space restore_current_progspace;
-      set_current_program_space (inf->inferior->pspace);
+      thread_info *thr = any_thread_of_inferior (inf->inferior);
+      switch_to_thread_no_regs (thr);
 
       name = main_name ();
     }
diff --git a/gdb/testsuite/gdb.python/py-inferior.exp b/gdb/testsuite/gdb.python/py-inferior.exp
index 41e26878031..9b0643d63e2 100644
--- a/gdb/testsuite/gdb.python/py-inferior.exp
+++ b/gdb/testsuite/gdb.python/py-inferior.exp
@@ -90,6 +90,7 @@  gdb_py_test_silent_cmd "python addr = gdb.selected_frame ().read_var ('str')" \
   "read str address" 0
 gdb_py_test_silent_cmd "python astr = gdb.inferiors()\[0\].read_memory (addr, 5); print(str)" \
   "read str contents" 1
+gdb_test "python print(astr\[0\])" .*
 gdb_py_test_silent_cmd "python a = bytes('a', 'ascii')" "" 0
 gdb_py_test_silent_cmd "python astr\[1\] = a" "change str" 0
 gdb_py_test_silent_cmd "python gdb.inferiors()\[0\].write_memory (addr, astr)" \
@@ -97,6 +98,10 @@  gdb_py_test_silent_cmd "python gdb.inferiors()\[0\].write_memory (addr, astr)" \
 gdb_test "print str" " = \"hallo, testsuite\"" \
   "ensure str was changed in the inferior"
 
+# Add a new inferior here, so we can test that operations work on the
+# correct inferior.
+set num [add_inferior]
+
 # Test memory search.
 
 set hex_number {0x[0-9a-fA-F][0-9a-fA-F]*}
@@ -114,6 +119,9 @@  with_test_prefix "string" {
     gdb_test_no_output "py start_addr = search_buf.address"
     gdb_test_no_output "py length = search_buf.type.sizeof"
 
+    # Switch to the new inferior before testing.
+    gdb_test "inferior $num" ".*" "switch to inferior $num"
+
     gdb_test "py print (gdb.inferiors()\[0\].search_memory (start_addr, length, 'aaa'))" \
 	"${one_pattern_found}" "find string pattern"
 
@@ -127,6 +135,23 @@  with_test_prefix "string" {
 	"${one_pattern_found}" "pattern found at end of range"
 }
 
+# While still in the new inferior, test reading and writing memory
+# again.
+gdb_py_test_silent_cmd "python astr = gdb.inferiors()\[0\].read_memory (addr, 5); print(str)" \
+    "read str while other inferior selected" 1
+gdb_test "python print(astr\[1\])" "b'a'" \
+    "print a character from the string"
+gdb_py_test_silent_cmd "python astr\[1\] = b'X'" "change str again" 0
+gdb_py_test_silent_cmd "python gdb.inferiors()\[0\].write_memory (addr, astr)" \
+    "write str while other inferior selected" 1
+
+gdb_test "inferior 1" ".*" "switch back to inferior 1"
+
+gdb_test "print str" " = \"hXllo, testsuite\"" \
+    "ensure str was changed while other inferior selected"
+
+gdb_test_no_output "remove-inferiors $num" "remove-inferiors $num"
+
 # Import struct to pack the following patterns.
 gdb_test_no_output "py from struct import *"