libxslt: revision bump to address open CVEs

- Add patches copied from Debian to address open CVEs
- Update mail address of maintainer
- Fix a typo
- Add --disable-silent-rules for verbose build output

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

libs/libxslt/patches/0015-Lower-bound-for-format-token-a.patch

@@ -0,0 +1,75 @@
+From 405034286fbdd6166229335b7203a41bf53b40fc Mon Sep 17 00:00:00 2001
+From: Nick Wellnhofer <wellnhofer@aevum.de>
+Date: Sun, 10 Apr 2016 13:11:31 +0200
+Subject: [PATCH] Lower bound for format token "a"
+
+Handle xsl:number with format "a" and value 0 according to XSLT 2.0.
+
+Fixes an OOB array access in xsltNumberFormatAlpha.
+---
+ libxslt/numbers.c | 33 ++++++++++++++++++++++++---------
+ 1 file changed, 24 insertions(+), 9 deletions(-)
+
+diff --git a/libxslt/numbers.c b/libxslt/numbers.c
+index a3cabcf..af52883 100644
+--- a/libxslt/numbers.c
++++ b/libxslt/numbers.c
+@@ -227,7 +227,8 @@ xsltNumberFormatDecimal(xmlBufferPtr buffer,
+ }
+ 
+ static void
+-xsltNumberFormatAlpha(xmlBufferPtr buffer,
++xsltNumberFormatAlpha(xsltNumberDataPtr data,
++		      xmlBufferPtr buffer,
+ 		      double number,
+ 		      int is_upper)
+ {
+@@ -237,6 +238,26 @@ xsltNumberFormatAlpha(xmlBufferPtr buffer,
+     char *alpha_list;
+     double alpha_size = (double)(sizeof(alpha_upper_list) - 1);
+ 
++    /*
++     * XSLT 1.0 isn't clear on how to handle zero, but XSLT 2.0 says:
++     *
++     *     For all format tokens other than the first kind above (one that
++     *     consists of decimal digits), there may be implementation-defined
++     *     lower and upper bounds on the range of numbers that can be
++     *     formatted using this format token; indeed, for some numbering
++     *     sequences there may be intrinsic limits. [...] Numbers that fall
++     *     outside this range must be formatted using the format token 1.
++     *
++     * The "a" token has an intrinsic lower limit of 1.
++     */
++    if (number < 1.0) {
++        xsltNumberFormatDecimal(buffer, number, '0', 1,
++                                data->digitsPerGroup,
++                                data->groupingCharacter,
++                                data->groupingCharacterLen);
++        return;
++    }
++
+     /* Build buffer from back */
+     pointer = &temp_string[sizeof(temp_string)];
+     *(--pointer) = 0;
+@@ -500,16 +521,10 @@ xsltNumberFormatInsertNumbers(xsltNumberDataPtr data,
+ 
+ 		switch (token->token) {
+ 		case 'A':
+-		    xsltNumberFormatAlpha(buffer,
+-					  number,
+-					  TRUE);
+-
++		    xsltNumberFormatAlpha(data, buffer, number, TRUE);
+ 		    break;
+ 		case 'a':
+-		    xsltNumberFormatAlpha(buffer,
+-					  number,
+-					  FALSE);
+-
++		    xsltNumberFormatAlpha(data, buffer, number, FALSE);
+ 		    break;
+ 		case 'I':
+ 		    xsltNumberFormatRoman(buffer,
+-- 
+2.8.1
+