[goffice] GOFormat: restrict to sane number of decimals.

[Morten Welinder <mortenw src gnome org>]

commit c87a4c642ebd0fbf388a8378409f70fae4eb7461
Author: Morten Welinder <terra gnome org>
Date:   Tue Aug 17 09:09:42 2010 -0400

    GOFormat: restrict to sane number of decimals.

 ChangeLog                 |    6 ++++++
 NEWS                      |    3 +++
 goffice/utils/go-format.c |   22 ++++++++++++++--------
 3 files changed, 23 insertions(+), 8 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 84a9e15..2049522 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-08-17  Morten Welinder  <terra gnome org>
+
+	* goffice/utils/go-format.c (go_format_generate_number_str,
+	go_format_generate_scientific_str,
+	go_format_generate_accounting_str): Limit number of decimals.
+
 2010-08-16  Morten Welinder <terra gnome org>
 
 	* configure.in: Post-release bump.
diff --git a/NEWS b/NEWS
index 1f3ce32..27a4229 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,8 @@
 goffice 0.8.10:
 
+Morten:
+	* Limit formats to sane number of decimals.  [#627066]
+
 --------------------------------------------------------------------------
 goffice 0.8.9:
 
diff --git a/goffice/utils/go-format.c b/goffice/utils/go-format.c
index d7a0502..2e9008d 100644
--- a/goffice/utils/go-format.c
+++ b/goffice/utils/go-format.c
@@ -54,6 +54,7 @@
 #define ALLOW_EE_MARKUP
 #define ALLOW_PI_SLASH
 #define ALLOW_NEGATIVE_TIMES
+#define MAX_DECIMALS 100
 
 /* ------------------------------------------------------------------------- */
 
@@ -3918,7 +3919,7 @@ go_format_inc_precision (GOFormat const *fmt)
 		case GO_FORMAT_CURRENCY:
 		case GO_FORMAT_ACCOUNTING:
 		case GO_FORMAT_PERCENTAGE:
-			if (details.num_decimals >= 30)
+			if (details.num_decimals >= MAX_DECIMALS)
 				return NULL;
 			details.num_decimals++;
 			go_format_generate_str (res, &details);
@@ -4993,8 +4994,8 @@ go_format_generate_number_str (GString *dst,
 	size_t init_len = dst->len;
 	size_t plain_len;
 
-	if (min_digits < 0) min_digits = 0;
-	if (num_decimals < 0) num_decimals = 0;
+	min_digits = CLAMP (min_digits, 0, MAX_DECIMALS);
+	num_decimals = CLAMP (num_decimals, 0, MAX_DECIMALS);
 
 	if (prefix)
 		g_string_append (dst, prefix);
@@ -5048,15 +5049,19 @@ go_format_generate_number_str (GString *dst,
 static void
 go_format_generate_scientific_str (GString *dst, GOFormatDetails const *details)
 {
-	go_string_append_c_n (dst, '#', MAX (0, details->exponent_step - 1));
+	/* Maximum not terribly important. */
+	int step = CLAMP (details->exponent_step, 1, 10);
+	int num_decimals = CLAMP (details->num_decimals, 0, MAX_DECIMALS);
+
+	go_string_append_c_n (dst, '#', step - 1);
 	if (details->simplify_mantissa)
 		g_string_append_c (dst, '#');
 	else
 		g_string_append_c (dst, '0');
 
-	if (details->num_decimals > 0) {
+	if (num_decimals > 0) {
 		g_string_append_c (dst, '.');
-		go_string_append_c_n (dst, '0', details->num_decimals);
+		go_string_append_c_n (dst, '0', num_decimals);
 	}
 
 	if (details->use_markup)
@@ -5071,6 +5076,7 @@ static void
 go_format_generate_accounting_str (GString *dst,
 				   GOFormatDetails const *details)
 {
+	int num_decimals = CLAMP (details->num_decimals, 0, MAX_DECIMALS);
 	GString *num = g_string_new (NULL);
 	GString *sym = g_string_new (NULL);
 	GString *q = g_string_new (NULL);
@@ -5099,10 +5105,10 @@ go_format_generate_accounting_str (GString *dst,
 	}
 
 	go_format_generate_number_str (num, details->min_digits,
-				       details->num_decimals,
+				       num_decimals,
 				       details->thousands_sep,
 				       FALSE, FALSE, NULL, NULL);
-	go_string_append_c_n (q, '?', details->num_decimals);
+	go_string_append_c_n (q, '?', num_decimals);
 
 	if (currency->precedes) {
 		g_string_append (sym, quote);