format-parser: Fix parse_format_specifier() failure case.

When the current token is an identifier that takes the abstract syntax
of a format specifier, but its "name" part is not a valid format name,
parse_format_specifier() returned false but still consumed the token.
This is a potential issue for callers that want to report an error that
mentions the identifier, e.g. parse_primary(), although the current lexer
tends to retain the same identifier when the new token is not an
identifier.

diff --git a/src/language/lexer/format-parser.c b/src/language/lexer/format-parser.c
index 39dbacbf238bba69371b6ffc5c803f378dbde454..9adbeb1552bd13a398cb39ccc2b67777080aeaaf 100644 (file)
--- a/src/language/lexer/format-parser.c
+++ b/src/language/lexer/format-parser.c
@@ -33,18 +33,10 @@
 #include "gettext.h"
 #define _(msgid) gettext (msgid)
 
-/* Parses a token taking the form of a format specifier and
-   returns true only if successful.  Emits an error message on
-   failure.  Stores a null-terminated string representing the
-   format type in TYPE, and the width and number of decimal
-   places in *WIDTH and *DECIMALS.
-
-   TYPE is not checked as to whether it is really the name of a
-   format.  Both width and decimals are considered optional.  If
-   missing, *WIDTH or *DECIMALS or both will be set to 0. */
-bool
-parse_abstract_format_specifier (struct lexer *lexer, char type[FMT_TYPE_LEN_MAX + 1],
-                                 int *width, int *decimals)
+static bool
+parse_abstract_format_specifier__ (struct lexer *lexer,
+                                   char type[FMT_TYPE_LEN_MAX + 1],
+                                   int *width, int *decimals)
 {
   struct substring s;
   struct substring type_ss, width_ss, decimals_ss;
@@ -81,14 +73,33 @@ parse_abstract_format_specifier (struct lexer *lexer, char type[FMT_TYPE_LEN_MAX
   *width = strtol (ss_data (width_ss), NULL, 10);
   *decimals = has_decimals ? strtol (ss_data (decimals_ss), NULL, 10) : 0;
 
-  lex_get (lexer);
   return true;
 
- error:
+error:
   lex_error (lexer, _("expecting valid format specifier"));
   return false;
 }
 
+/* Parses a token taking the form of a format specifier and
+   returns true only if successful.  Emits an error message on
+   failure.  Stores a null-terminated string representing the
+   format type in TYPE, and the width and number of decimal
+   places in *WIDTH and *DECIMALS.
+
+   TYPE is not checked as to whether it is really the name of a
+   format.  Both width and decimals are considered optional.  If
+   missing, *WIDTH or *DECIMALS or both will be set to 0. */
+bool
+parse_abstract_format_specifier (struct lexer *lexer,
+                                 char type[FMT_TYPE_LEN_MAX + 1],
+                                 int *width, int *decimals)
+{
+  bool ok = parse_abstract_format_specifier__ (lexer, type, width, decimals);
+  if (ok)
+    lex_get (lexer);
+  return ok;
+}
+
 /* Parses a format specifier from the token stream and returns
    true only if successful.  Emits an error message on
    failure.  The caller should call check_input_specifier() or
@@ -99,7 +110,7 @@ parse_format_specifier (struct lexer *lexer, struct fmt_spec *format)
 {
   char type[FMT_TYPE_LEN_MAX + 1];
 
-  if (!parse_abstract_format_specifier (lexer, type, &format->w, &format->d))
+  if (!parse_abstract_format_specifier__ (lexer, type, &format->w, &format->d))
     return false;
 
   if (!fmt_from_name (type, &format->type))
@@ -108,6 +119,7 @@ parse_format_specifier (struct lexer *lexer, struct fmt_spec *format)
       return false;
     }
 
+  lex_get (lexer);
   return true;
 }