Bash-5.0 patch 2: fix expansion of aliases whose value ends with an unquoted tab

Author: Chet Ramey

parse.y

@@ -2557,12 +2557,14 @@ next_alias_char:
   if (uc == 0 && pushed_string_list && pushed_string_list->flags != PSH_SOURCE &&
       pushed_string_list->flags != PSH_DPAREN &&
       (parser_state & PST_COMMENT) == 0 &&
+      (parser_state & PST_ENDALIAS) == 0 &&	/* only once */
       shell_input_line_index > 0 &&
-      shell_input_line[shell_input_line_index-1] != ' ' &&
+      shellblank (shell_input_line[shell_input_line_index-1]) == 0 &&
       shell_input_line[shell_input_line_index-1] != '\n' &&
       shellmeta (shell_input_line[shell_input_line_index-1]) == 0 &&
       (current_delimiter (dstack) != '\'' && current_delimiter (dstack) != '"'))
     {
+      parser_state |= PST_ENDALIAS;
       return ' ';	/* END_ALIAS */
     }
 #endif
@@ -2571,6 +2573,7 @@ pop_alias:
   /* This case works for PSH_DPAREN as well */
   if (uc == 0 && pushed_string_list && pushed_string_list->flags != PSH_SOURCE)
     {
+      parser_state &= ~PST_ENDALIAS;
       pop_string ();
       uc = shell_input_line[shell_input_line_index];
       if (uc)

parser.h

@@ -47,6 +47,7 @@
 #define PST_REPARSE	0x040000	/* re-parsing in parse_string_to_word_list */
 #define PST_REDIRLIST	0x080000	/* parsing a list of redirections preceding a simple command name */
 #define PST_COMMENT	0x100000	/* parsing a shell comment; used by aliases */
+#define PST_ENDALIAS	0x200000	/* just finished expanding and consuming an alias */
 
 /* Definition of the delimiter stack.  Needed by parse.y and bashhist.c. */
 struct dstack {

patchlevel.h

@@ -25,6 +25,6 @@
    regexp `^#define[ 	]*PATCHLEVEL', since that's what support/mkversion.sh
    looks for to find the patch level (for the sccs version string). */
 
-#define PATCHLEVEL 1
+#define PATCHLEVEL 2
 
 #endif /* _PATCHLEVEL_H_ */

y.tab.c

@@ -4873,12 +4873,14 @@ shell_getc (remove_quoted_newline)
   if (uc == 0 && pushed_string_list && pushed_string_list->flags != PSH_SOURCE &&
       pushed_string_list->flags != PSH_DPAREN &&
       (parser_state & PST_COMMENT) == 0 &&
+      (parser_state & PST_ENDALIAS) == 0 &&	/* only once */
       shell_input_line_index > 0 &&
-      shell_input_line[shell_input_line_index-1] != ' ' &&
+      shellblank (shell_input_line[shell_input_line_index-1]) == 0 &&
       shell_input_line[shell_input_line_index-1] != '\n' &&
       shellmeta (shell_input_line[shell_input_line_index-1]) == 0 &&
       (current_delimiter (dstack) != '\'' && current_delimiter (dstack) != '"'))
     {
+      parser_state |= PST_ENDALIAS;
       return ' ';	/* END_ALIAS */
     }
 #endif
@@ -4887,6 +4889,7 @@ shell_getc (remove_quoted_newline)
   /* This case works for PSH_DPAREN as well */
   if (uc == 0 && pushed_string_list && pushed_string_list->flags != PSH_SOURCE)
     {
+      parser_state &= ~PST_ENDALIAS;
       pop_string ();
       uc = shell_input_line[shell_input_line_index];
       if (uc)