Bug 796919 - Leading '+' character not accepted in amount when value surrounded by quotes

Use a variant of xaccParseAmount that allows to ignore the locale's positive_sign character
or the + sign if locale doesn't define a positive_sign character.

In a future redesign it would probably be better to replace use
of xaccParseAmount with some variant of the gnc-expression-parser
but that would require more that a few tweaks to get right.

gnucash/import-export/csv-imp/gnc-imp-props-price.cpp

@@ -72,7 +72,7 @@ GncNumeric parse_amount_price (const std::string &str, int currency_format)
     {
     case 0:
         /* Currency locale */
-        if (!(xaccParseAmount (str_no_symbols.c_str(), TRUE, &val, &endptr)))
+        if (!(xaccParseAmountPosSign (str_no_symbols.c_str(), TRUE, &val, &endptr, TRUE)))
             throw std::invalid_argument (_("Value can't be parsed into a number using the selected currency format."));
         break;
     case 1:

gnucash/import-export/csv-imp/gnc-imp-props-tx.cpp

@@ -120,7 +120,7 @@ GncNumeric parse_amount (const std::string &str, int currency_format)
     {
     case 0:
         /* Currency locale */
-        if (!(xaccParseAmount (str_no_symbols.c_str(), TRUE, &val, &endptr)))
+        if (!(xaccParseAmountPosSign (str_no_symbols.c_str(), TRUE, &val, &endptr, TRUE)))
             throw std::invalid_argument (_("Value can't be parsed into a number using the selected currency format."));
         break;
     case 1:

libgnucash/app-utils/gnc-ui-util.c

@@ -1985,12 +1985,21 @@ multiplier (int num_decimals)
 gboolean
 xaccParseAmount (const char * in_str, gboolean monetary, gnc_numeric *result,
                  char **endstr)
+{
+    return xaccParseAmountPosSign (in_str, monetary, result, endstr, FALSE);
+}
+
+gboolean
+xaccParseAmountPosSign (const char * in_str, gboolean monetary, gnc_numeric *result,
+                        char **endstr, gboolean skip)
 {
     struct lconv *lc = gnc_localeconv();
 
     gunichar negative_sign;
     gunichar decimal_point;
     gunichar group_separator;
+    gchar *ignore = NULL;
+    char *plus_sign = "+";
     char *group;
 
     negative_sign = g_utf8_get_char(lc->negative_sign);
@@ -2007,8 +2016,18 @@ xaccParseAmount (const char * in_str, gboolean monetary, gnc_numeric *result,
         group = lc->grouping;
     }
 
+    if (skip)
+    {
+        /* We want the locale's positive sign to be ignored.
+        * If the locale doesn't specify one, we assume "+" as
+        * an optional positive sign and ignore that */
+        ignore = lc->positive_sign;
+        if (!ignore || !*ignore)
+            ignore = plus_sign;
+    }
+
     return xaccParseAmountExtended(in_str, monetary, negative_sign, decimal_point,
-                                   group_separator, group, NULL, result, endstr);
+                                   group_separator, group, ignore, result, endstr);
 }
 
 /* Note: xaccParseAmountExtended causes test-print-parse-amount

libgnucash/app-utils/gnc-ui-util.h

@@ -321,6 +321,19 @@ gchar *numeric_to_words(gnc_numeric val);
 gboolean xaccParseAmount (const char * in_str, gboolean monetary,
                           gnc_numeric *result, char **endstr);
 
+/*
+ * xaccParseAmountPosSign is just like xaccParseAmount except the
+ * caller can choose whether the locale's postive sign (or in absense
+ * the '+') character is ignored. Setting skip to TRUE will cause
+ * the function to ignore any positive sign. Setting it to FALSE,
+ * and positive signs will be treated as unrecognized characters.
+ * xaccParseAmount will run as if skip is FALSE for compatibility
+ * reasons (gnc-expression-parser depends on this behaviour).
+ */
+gboolean
+xaccParseAmountPosSign (const char * in_str, gboolean monetary, gnc_numeric *result,
+                        char **endstr, gboolean skip);
+
 /*
  * xaccParseAmountExtended is just like xaccParseAmount except the
  * caller must provide all the locale-specific information.