02/02: gnu: libxslt: Make generated documentation reproducible.

[Mathieu Lirzin]

mthl pushed a commit to branch core-updates
in repository guix.

commit c74c7c13176a97c84ace3e2417456ddc561b0638
Author: Mathieu Lirzin <address@hidden>
Date:   Mon Apr 18 23:21:42 2016 +0200

    gnu: libxslt: Make generated documentation reproducible.
    
    * gnu/packages/patches/libxslt-generated-ids.patch: New file.
    * gnu/packages/patches/libxslt-remove-date-timestamps.patch: Likewise.
    * gnu/packages/xml.scm (libxslt)[source]: Use them.
    * gnu/local.mk (dist_patch_DATA): Add them.
---
 gnu/local.mk                                       |    2 +
 gnu/packages/patches/libxslt-generated-ids.patch   |  173 ++++++++++++++++++++
 .../patches/libxslt-remove-date-timestamps.patch   |   66 ++++++++
 gnu/packages/xml.scm                               |    5 +-
 4 files changed, 245 insertions(+), 1 deletion(-)

diff --git a/gnu/local.mk b/gnu/local.mk
index 8d945e8..da377fd 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -603,6 +603,8 @@ dist_patch_DATA =                                           
\
   gnu/packages/patches/libwmf-CVE-2015-4695.patch              \
   gnu/packages/patches/libwmf-CVE-2015-4696.patch              \
   gnu/packages/patches/libxslt-CVE-2015-7995.patch             \
+  gnu/packages/patches/libxslt-generated-ids.patch             \
+  gnu/packages/patches/libxslt-remove-date-timestamps.patch    \
   gnu/packages/patches/lirc-localstatedir.patch                        \
   gnu/packages/patches/libpthread-glibc-preparation.patch      \
   gnu/packages/patches/lm-sensors-hwmon-attrs.patch            \
diff --git a/gnu/packages/patches/libxslt-generated-ids.patch 
b/gnu/packages/patches/libxslt-generated-ids.patch
new file mode 100644
index 0000000..4273875
--- /dev/null
+++ b/gnu/packages/patches/libxslt-generated-ids.patch
@@ -0,0 +1,173 @@
+This makes generated IDs deterministic.
+
+Written by Daniel Veillard.
+
+This should be fixed in next release (2.29).
+See https://bugzilla.gnome.org/show_bug.cgi?id=751621.
+
+diff --git a/libxslt/functions.c b/libxslt/functions.c
+index 6448bde..5b00a6d 100644
+--- a/libxslt/functions.c
++++ b/libxslt/functions.c
+@@ -651,6 +651,63 @@ xsltFormatNumberFunction(xmlXPathParserContextPtr ctxt, 
int nargs)
+ }
+ 
+ /**
++ * xsltCleanupIds:
++ * @ctxt: the transformation context
++ * @root: the root of the resulting document
++ *
++ * This clean up ids which may have been saved in Element contents
++ * by xsltGenerateIdFunction() to provide stable IDs on elements.
++ *
++ * Returns the number of items cleaned or -1 in case of error
++ */
++int
++xsltCleanupIds(xsltTransformContextPtr ctxt, xmlNodePtr root) {
++    xmlNodePtr cur;
++    int count = 0;
++
++    if ((ctxt == NULL) || (root == NULL))
++        return(-1);
++    if (root->type != XML_ELEMENT_NODE)
++        return(-1);
++
++    cur = root;
++    while (cur != NULL) {
++      if (cur->type == XML_ELEMENT_NODE) {
++          if (cur->content != NULL) {
++              cur->content = NULL;
++              count++;
++          }
++          if (cur->children != NULL) {
++              cur = cur->children;
++              continue;
++          }
++      }
++      if (cur->next != NULL) {
++          cur = cur->next;
++          continue;
++      }
++      do {
++          cur = cur->parent;
++          if (cur == NULL)
++              break;
++          if (cur == (xmlNodePtr) root) {
++              cur = NULL;
++              break;
++          }
++          if (cur->next != NULL) {
++              cur = cur->next;
++              break;
++          }
++      } while (cur != NULL);
++    }
++
++fprintf(stderr, "Attributed %d IDs for element, cleaned up %d\n",
++        ctxt->nextid, count);
++
++    return(count);
++}
++
++/**
+  * xsltGenerateIdFunction:
+  * @ctxt:  the XPath Parser context
+  * @nargs:  the number of arguments
+@@ -701,7 +758,39 @@ xsltGenerateIdFunction(xmlXPathParserContextPtr ctxt, int 
nargs){
+     if (obj)
+         xmlXPathFreeObject(obj);
+ 
+-    val = (long)((char *)cur - (char *)&base_address);
++    /*
++     * Try to provide stable ID for generated document:
++     *   - usually ID are computed to be placed on elements via attributes
++     *     so using the element as the node for the ID
++     *   - the cur->content should be a correct placeholder for this, we use
++     *     it to hold element node numbers in xmlXPathOrderDocElems to
++     *     speed up XPath too
++     *   - xsltCleanupIds() clean them up before handing the XSLT output
++     *     to the API client.
++     *   - other nodes types use the node address method but that should
++     *     not end up in resulting document ID
++     *   - we can enable this by default without risk of performance issues
++     *     only the one pass xsltCleanupIds() is added
++     */
++    if (cur->type == XML_ELEMENT_NODE) {
++        if (cur->content == NULL) {
++          xsltTransformContextPtr tctxt;
++
++          tctxt = xsltXPathGetTransformContext(ctxt);
++          if (tctxt == NULL) {
++              val = (long)((char *)cur - (char *)&base_address);
++          } else {
++              tctxt->nextid++;
++              val = tctxt->nextid;
++              cur->content = (void *) (val);
++          }
++      } else {
++          val = (long) cur->content;
++      }
++    } else {
++      val = (long)((char *)cur - (char *)&base_address);
++    }
++
+     if (val >= 0) {
+       sprintf((char *)str, "idp%ld", val);
+     } else {
+diff --git a/libxslt/functions.h b/libxslt/functions.h
+index e0e0bf9..4a1e163 100644
+--- a/libxslt/functions.h
++++ b/libxslt/functions.h
+@@ -64,6 +64,13 @@ XSLTPUBFUN void XSLTCALL
+                                        int nargs);
+ 
+ /*
++ * Cleanup for ID generation
++ */
++XSLTPUBFUN int XSLTCALL
++      xsltCleanupIds                  (xsltTransformContextPtr ctxt,
++                                       xmlNodePtr root);
++
++/*
+  * And the registration
+  */
+ 
+diff --git a/libxslt/transform.c b/libxslt/transform.c
+index 24f9eb2..2bdf6bf 100644
+--- a/libxslt/transform.c
++++ b/libxslt/transform.c
+@@ -700,6 +700,7 @@ xsltNewTransformContext(xsltStylesheetPtr style, xmlDocPtr 
doc) {
+     cur->traceCode = (unsigned long*) &xsltDefaultTrace;
+     cur->xinclude = xsltGetXIncludeDefault();
+     cur->keyInitLevel = 0;
++    cur->nextid = 0;
+ 
+     return(cur);
+ 
+@@ -6092,6 +6093,13 @@ xsltApplyStylesheetInternal(xsltStylesheetPtr style, 
xmlDocPtr doc,
+     if (root != NULL) {
+         const xmlChar *doctype = NULL;
+ 
++        /*
++       * cleanup ids which may have been saved in Elements content ptrs
++       */
++      if (ctxt->nextid != 0) {
++          xsltCleanupIds(ctxt, root);
++      }
++
+         if ((root->ns != NULL) && (root->ns->prefix != NULL))
+           doctype = xmlDictQLookup(ctxt->dict, root->ns->prefix, root->name);
+       if (doctype == NULL)
+diff --git a/libxslt/xsltInternals.h b/libxslt/xsltInternals.h
+index 95e8fe6..8eedae4 100644
+--- a/libxslt/xsltInternals.h
++++ b/libxslt/xsltInternals.h
+@@ -1786,6 +1786,8 @@ struct _xsltTransformContext {
+     int funcLevel;      /* Needed to catch recursive functions issues */
+     int maxTemplateDepth;
+     int maxTemplateVars;
++
++    unsigned long nextid;/* for generating stable ids */
+ };
+ 
+ /**
diff --git a/gnu/packages/patches/libxslt-remove-date-timestamps.patch 
b/gnu/packages/patches/libxslt-remove-date-timestamps.patch
new file mode 100644
index 0000000..51470d0
--- /dev/null
+++ b/gnu/packages/patches/libxslt-remove-date-timestamps.patch
@@ -0,0 +1,66 @@
+Use deterministic SOURCE_DATE_EPOCH for embedded timestamps in generated 
documentation.
+
+Written by Eduard Sanou.
+
+https://bugzilla.gnome.org/show_bug.cgi?id=758148
+
+--- libxslt-1.1.28.orig/libexslt/date.c
++++ libxslt-1.1.28/libexslt/date.c
+@@ -46,6 +46,7 @@
+ #include "exslt.h"
+ 
+ #include <string.h>
++#include <errno.h>
+ 
+ #ifdef HAVE_MATH_H
+ #include <math.h>
+@@ -747,21 +748,46 @@ static exsltDateValPtr
+ exsltDateCurrent (void)
+ {
+     struct tm localTm, gmTm;
++    struct tm *tb = NULL;
+     time_t secs;
+     int local_s, gm_s;
+     exsltDateValPtr ret;
++    char *source_date_epoch;
+ 
+     ret = exsltDateCreateDate(XS_DATETIME);
+     if (ret == NULL)
+         return NULL;
+ 
+-    /* get current time */
+     secs    = time(NULL);
++    /*
++     * Allow the date and time to be set externally by an exported
++     * environment variable to enable reproducible builds.
++     */
++    source_date_epoch = getenv("SOURCE_DATE_EPOCH");
++    if (source_date_epoch) {
++      errno = 0;
++      secs = (time_t) strtol (source_date_epoch, NULL, 10);
++      if (errno == 0) {
++          tb = gmtime(&secs);
++          if (tb == NULL) {
++          /* SOURCE_DATE_EPOCH is not a valid date */
++              return NULL;
++          } else {
++              localTm = *tb;
++          }
++      } else {
++          /* SOURCE_DATE_EPOCH is not a valid number */
++          return NULL;
++      }
++    } else {
++      /* get current time */
+ #if HAVE_LOCALTIME_R
+-    localtime_r(&secs, &localTm);
++      localtime_r(&secs, &localTm);
+ #else
+-    localTm = *localtime(&secs);
++      localTm = *localtime(&secs);
+ #endif
++    }
++
+ 
+     /* get real year, not years since 1900 */
+     ret->value.date.year = localTm.tm_year + 1900;
diff --git a/gnu/packages/xml.scm b/gnu/packages/xml.scm
index 838ce34..538996f 100644
--- a/gnu/packages/xml.scm
+++ b/gnu/packages/xml.scm
@@ -7,6 +7,7 @@
 ;;; Copyright © 2015, 2016 Mark H Weaver <address@hidden>
 ;;; Copyright © 2015 Efraim Flashner <address@hidden>
 ;;; Copyright © 2015 Raimon Grau <address@hidden>
+;;; Copyright © 2016 Mathieu Lirzin <address@hidden>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -131,7 +132,9 @@ project (but it is usable outside of the Gnome platform).")
              (sha256
               (base32
                "13029baw9kkyjgr7q3jccw2mz38amq7mmpr5p3bh775qawd1bisz"))
-             (patches (search-patches "libxslt-CVE-2015-7995.patch"))))
+             (patches (search-patches "libxslt-generated-ids.patch"
+                                      "libxslt-remove-date-timestamps.patch"
+                                      "libxslt-CVE-2015-7995.patch"))))
     (build-system gnu-build-system)
     (home-page "http://xmlsoft.org/XSLT/index.html";)
     (synopsis "C library for applying XSLT stylesheets to XML documents")