Fix TID parser bug

I noticed this inconsistency in the error messages below:

 (gdb) print --1
 Left operand of assignment is not an lvalue.

 (gdb) thread apply 1 print --1

 Thread 1 (Thread 0x7ffff7fb6740 (LWP 17805)):
 inverted range

The "inverted range" error happens because get_number_trailer returns
0 to indicate error, but number_or_range_parser::get_number is not
checking for that.  I tried detected the error there, but that doesn't
work because number_of_range_parser is used in places that _do_ want
to legitimately handle 0.  IMO we should fix get_number_trailer's
interface or use something else when we want to parse 0 too.

I've decided to fix it in a different way, similarly to how
number_or_range_parser::finished was changed in commit 529c08b25ec7
("Add helper functions parse_flags and parse_flags_qcs").

Seems like a good change, even if we tweaked
number_or_range_parser::get_number, as it simplifies
thread_apply_command and makes them consistent with
number_or_range_parser::finished().

We now get the same error message in both cases:

 (gdb) print --1
 Left operand of assignment is not an lvalue.

 (gdb) thread apply 1 print --1

 Thread 1 (Thread 0x7ffff7fb6740 (LWP 17805)):
 Left operand of assignment is not an lvalue.

gdb/ChangeLog:
2019-06-13  Pedro Alves  <palves@redhat.com>

	* thread.c (thread_apply_command): Adjust TID parsing.
	* tid-parse.c (tid_range_parser::finished): Ensure parsing end is
	detected before end of string.
	(tid_is_in_list): Error out if LIST is invalid.

gdb/testsuite/ChangeLog:
2019-06-13  Pedro Alves  <palves@redhat.com>

	* gdb.multi/tids.exp: Adjust expected output.  Add "thread apply 1
	foo --1" test.

gdb/ChangeLog

@@ -1,3 +1,10 @@
+2019-06-13  Pedro Alves  <palves@redhat.com>
+
+	* thread.c (thread_apply_command): Adjust TID parsing.
+	* tid-parse.c (tid_range_parser::finished): Ensure parsing end is
+	detected before end of string.
+	(tid_is_in_list): Error out if LIST is invalid.
+
 2019-06-13  Pedro Alves  <palves@redhat.com>
 
 	* completer.c (complete_line_internal_1): Rewind completion word

gdb/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2019-06-13  Pedro Alves  <palves@redhat.com>
+
+	* gdb.multi/tids.exp: Adjust expected output.  Add "thread apply 1
+	foo --1" test.
+
 2019-06-11  Bernhard Heckel  <bernhard.heckel@intel.com>
 
 	* gdb.fortran/block-data.f: New.

gdb/testsuite/gdb.multi/tids.exp

@@ -350,8 +350,13 @@ with_test_prefix "two inferiors" {
 	thr_apply_info_thr_error "${prefix}1-" "inverted range"
 	thr_apply_info_thr_error "${prefix}2-1" "inverted range"
 	thr_apply_info_thr_error "${prefix}2-\$one" "inverted range"
-	thr_apply_info_thr_error "${prefix}-1" "negative value"
+	if {$prefix == ""} {
-	thr_apply_info_thr_error "${prefix}-\$one" "negative value"
+	    thr_apply_info_thr_error "${prefix}-1" "Invalid thread ID: -1"
+	    thr_apply_info_thr_error "${prefix}-\$one" "Invalid thread ID: -\\\$one"
+	} else {
+	    thr_apply_info_thr_error "${prefix}-1" "negative value"
+	    thr_apply_info_thr_error "${prefix}-\$one" "negative value"
+	}
 	thr_apply_info_thr_error "${prefix}\$minus_one" \
 	    "negative value: ${prefix_re}\\\$minus_one"
 
@@ -374,6 +379,13 @@ with_test_prefix "two inferiors" {
 	gdb_test "thread apply 1.*" $output
     }
 
+    # Check that thread ID list parsing stops at the non-number token
+    # "foo" in a corner case where the "foo" is followed by hyphens.
+    # In this corner case, GDB used to skip past "foo", and then parse
+    # "--1" as a tid range for the current inferior.
+    gdb_test "thread apply 1 foo --1" \
+	"Undefined command: \"foo\".  Try \"help\"\\."
+
     # Check that we do parse the inferior number and don't confuse it.
     gdb_test "info threads 3.1" \
 	"No threads match '3.1'\."

gdb/thread.c

@@ -1560,7 +1560,6 @@ thread_apply_command (const char *tidlist, int from_tty)
 {
   qcs_flags flags;
   const char *cmd = NULL;
-  const char *cmd_or_flags;
   tid_range_parser parser;
 
   if (tidlist == NULL || *tidlist == '\000')
@@ -1572,17 +1571,15 @@ thread_apply_command (const char *tidlist, int from_tty)
       int inf_num, thr_start, thr_end;
 
       if (!parser.get_tid_range (&inf_num, &thr_start, &thr_end))
-	{
+	break;
-	  cmd = parser.cur_tok ();
-	  break;
-	}
     }
 
-  cmd_or_flags = cmd;
+  cmd = parser.cur_tok ();
-  while (cmd != NULL && parse_flags_qcs ("thread apply", &cmd, &flags))
+
+  while (parse_flags_qcs ("thread apply", &cmd, &flags))
     ;
 
-  if (cmd == NULL)
+  if (*cmd == '\0')
     error (_("Please specify a command following the thread ID list"));
 
   if (tidlist == cmd || !isalpha (cmd[0]))
@@ -1591,7 +1588,7 @@ thread_apply_command (const char *tidlist, int from_tty)
   scoped_restore_current_thread restore_thread;
 
   parser.init (tidlist, current_inferior ()->num);
-  while (!parser.finished () && parser.cur_tok () < cmd_or_flags)
+  while (!parser.finished ())
     {
       struct thread_info *tp = NULL;
       struct inferior *inf;

gdb/tid-parse.c

@@ -139,7 +139,13 @@ tid_range_parser::finished () const
   switch (m_state)
     {
     case STATE_INFERIOR:
-      return *m_cur_tok == '\0';
+      /* Parsing is finished when at end of string or null string,
+	 or we are not in a range and not in front of an integer, negative
+	 integer, convenience var or negative convenience var.  */
+      return (*m_cur_tok == '\0'
+	      || !(isdigit (*m_cur_tok)
+		   || *m_cur_tok == '$'
+		   || *m_cur_tok == '*'));
     case STATE_THREAD_RANGE:
     case STATE_STAR_RANGE:
       return m_range_parser.finished ();
@@ -311,6 +317,8 @@ tid_is_in_list (const char *list, int default_inferior,
     return 1;
 
   tid_range_parser parser (list, default_inferior);
+  if (parser.finished ())
+    invalid_thread_id_error (parser.cur_tok ());
   while (!parser.finished ())
     {
       int tmp_inf, tmp_thr_start, tmp_thr_end;