[yelp] Deal correctly with the last line of output.

[Shaun McCance <shaunm src gnome org>]

commit 51e1771f8b0d3a0bbc7d0ad7ea351888f6bac5b7
Author: Rupert Swarbrick <rswarbrick gmail com>
Date:   Wed Dec 15 22:42:56 2010 +0000

    Deal correctly with the last line of output.
    
    Since we're parsing the whole thing in one pass, we can't know this is
    the last line until we're done, so we go through at the end and check
    whether there's an empty section. If so, we know what the title should
    look like, so we extract the information and put it somewhere more
    useful.

 libyelp/yelp-man-parser.c   |  163 +++++++++++++++++++++++++++++++++++++++++--
 stylesheets/man2html.xsl.in |   13 +++-
 2 files changed, 169 insertions(+), 7 deletions(-)
---
diff --git a/libyelp/yelp-man-parser.c b/libyelp/yelp-man-parser.c
index a821d3a..68eac81 100644
--- a/libyelp/yelp-man-parser.c
+++ b/libyelp/yelp-man-parser.c
@@ -186,6 +186,9 @@ static gboolean cheeky_call_parse_line (YelpManParser *parser,
                                         GError **error,
                                         gchar first_char,
                                         const gchar *text);
+static void cleanup_parsed_page (YelpManParser *parser);
+static gboolean parse_last_line (YelpManParser *parser, gchar* line);
+static void unicode_strstrip (gchar *str);
 
 /******************************************************************************/
 /* Translations for the 'C' command. This is indeed hackish, but the
@@ -396,6 +399,8 @@ yelp_man_parser_parse_file (YelpManParser *parser,
        }
     }
 
+    cleanup_parsed_page (parser);
+
     g_object_unref (parser->stream);
 
     return parser->doc;
@@ -568,8 +573,7 @@ parse_h (YelpManParser *parser, GError **error)
      */
     k = dx_to_em_count (parser, dx);
 
-    if ((parser->sheet_node) &&
-        ((!parser->last_char_was_space) || (k > 2))) {
+    if ((!parser->last_char_was_space) || (k > 2)) {
 
         k -= parser->N_count;
         if (k < 0) k = 0;
@@ -707,8 +711,9 @@ parse_body_text (YelpManParser *parser, GError **error)
                          xmlNewNode (NULL, BAD_CAST "section"));
     }
 
-    if (parser->section_state != SECTION_TITLE)
+    if (parser->section_state != SECTION_TITLE) {
         deal_with_newlines (parser);
+    }
 
     g_string_append (parser->accumulator, parser->buffer+1);
 
@@ -772,6 +777,7 @@ parse_n (YelpManParser *parser, GError **error)
         */
         right_truncate_common (parser->accumulator->str,
                                parser->title_str);
+        unicode_strstrip (parser->accumulator->str);
 
         xmlNewTextChild (parser->header,
                          NULL, BAD_CAST "collection",
@@ -848,9 +854,6 @@ parse_N (YelpManParser *parser, GError **error)
         RAISE_PARSE_ERROR ("Bizarrely many nbsps in N line: %s");
     }
 
-    deal_with_newlines (parser);
-    parser->last_char_was_space = FALSE;
-
     if (n < 0) {
         append_nbsps (parser, -n);
         parser->N_count += -n;
@@ -1046,3 +1049,151 @@ cheeky_call_parse_line (YelpManParser *parser, GError **error,
 
     return ret;
 }
+
+static void
+cleanup_parsed_page (YelpManParser *parser)
+{
+    /* First job: the last line usually has the version, date and
+     * title (again!). The code above misunderstands and parses this
+     * as a section, so we need to "undo" this and stick the data in
+     * the header where it belongs.
+     *
+     * parser->section_node should still point to it. We assume this
+     * has happened if it has exactly one child element (the <title>
+     * tag)
+     */
+    gchar *lastline;
+
+    if (xmlChildElementCount (parser->section_node) == 1) {
+        lastline = xmlNodeGetContent (parser->section_node);
+
+        /* If parse_last_line works, it sets the data from it in the
+           <header> tag, so delete the final section. */
+        if (parse_last_line (parser, lastline)) {
+            xmlUnlinkNode (parser->section_node);
+            xmlFreeNode (parser->section_node);
+        }
+        else {
+            /* Oh dear. This would be unexpected and doesn't seem to
+               happen with man on my system. But we probably shouldn't
+               ditch the info, so let's leave the <section> tag and
+               print a warning message to the console.
+            */
+            g_warning ("Unexpected final line in man document (%s)\n",
+                       lastline);
+        }
+
+        xmlFree (lastline);
+    }
+}
+
+static gchar *
+skip_whitespace (gchar *text)
+{
+    while (g_unichar_isspace (g_utf8_get_char (text))) {
+        text = g_utf8_next_char (text);
+    }
+    return text;
+}
+
+static gchar *
+last_non_whitespace (gchar *text)
+{
+    gchar *end = text + strlen(text);
+    gchar *prev;
+
+    prev = g_utf8_find_prev_char (text, end);
+    if (!prev) {
+        /* The string must have been zero-length. */
+        return NULL;
+    }
+
+    while (g_unichar_isspace (g_utf8_get_char (prev))) {
+        end = prev;
+        prev = g_utf8_find_prev_char (text, prev);
+        if (!prev) return NULL;
+    }
+    return end;
+}
+
+static gchar *
+find_contiguous_whitespace (gchar *text, guint ws_len)
+{
+    guint counter = 0;
+    gchar *ws_start;
+    while (*text) {
+        if (g_unichar_isspace (g_utf8_get_char (text))) {
+            if (!counter) ws_start = text;
+            counter++;
+        }
+        else counter = 0;
+
+        if (counter == ws_len) return ws_start;
+
+        text = g_utf8_next_char (text);
+    }
+    return NULL;
+}
+
+static gboolean
+parse_last_line (YelpManParser *parser, gchar* line)
+{
+    /* We expect a line of the form
+           '1.2.3      blah 2009       libfoo(1)'
+       where the spaces are all nbsp's.
+
+       Look for a gap of at least 3 in a row. If we find that, expand
+       either side and declare the stuff before to be the version
+       number and then the stuff afterwards to be the start of the
+       date. Then do the same thing on the next gap, if there is one.
+    */
+    gchar *gap, *date_start;
+
+    gchar *version;
+    gchar *date;
+
+    gap = find_contiguous_whitespace (line, 3);
+    if (!gap) return FALSE;
+
+    version = g_strndup (line, gap - line);
+
+    date_start = skip_whitespace (gap);
+
+    gap = find_contiguous_whitespace (date_start, 3);
+    if (!gap) return FALSE;
+
+    date = g_strndup (date_start, gap - date_start);
+
+    xmlNewProp (parser->header, BAD_CAST "version", version);
+    xmlNewProp (parser->header, BAD_CAST "date", date);
+
+    g_free (version);
+    g_free (date);
+
+    return TRUE;
+}
+
+/* This should work like g_strstrip, but that's an ASCII-only version
+ * and I want to strip the nbsp's that I so thoughtfully plaster
+ * stuff with...
+ */
+static void
+unicode_strstrip (gchar *str)
+{
+    gchar *start, *end;
+
+    if (str == NULL) return;
+
+    end = last_non_whitespace (str);
+
+    if (!end) {
+        /* String is zero-length or entirely whitespace */
+        *str = '\0';
+        return;
+    }
+    start = skip_whitespace (str);
+    g_utf8_next_char (end);
+
+    g_memmove (str, start, end - start);
+    *(str + (end - start)) = '\0';
+}
diff --git a/stylesheets/man2html.xsl.in b/stylesheets/man2html.xsl.in
index 5b3cd59..cc97e8a 100644
--- a/stylesheets/man2html.xsl.in
+++ b/stylesheets/man2html.xsl.in
@@ -31,13 +31,24 @@
   <div class="hgroup">
     <h1 class="title">
       <xsl:value-of select="title"/>
-      <xsl:text>(</xsl:text>
+      <xsl:text> (</xsl:text>
       <xsl:value-of select="section"/>
       <xsl:text>)</xsl:text>
     </h1>
     <h3 style="text-align: right;">
       <xsl:value-of select="collection"/>
     </h3>
+    <xsl:if test="@version or @date">
+      <p style="text-align: right">
+        <xsl:if test="@version">
+          Version: <xsl:value-of select="@version"/>
+        </xsl:if>
+        <xsl:if test="@version and @date"><br/></xsl:if>
+        <xsl:if test="@date">
+          Date: <xsl:value-of select="@date"/>
+        </xsl:if>
+      </p>
+    </xsl:if>
   </div>
 </xsl:template>