PDF outline headings, it turns out, should be encoded using either

PDFDocEncoding or UTF-16BE. (The PDF specification's index is
terribly bad; I looked under various obvious things such as
`character set' and `string literal' with no success, and I didn't
manage to find out what character set metadata string literals were
intended to be interpreted in until I discovered from another source
that the encoding was called PDFDocEncoding, and _then_ I was able
to look that up in the index. They should have been using Halibut! :-)

git-svn-id: svn://svn.tartarus.org/sgt/halibut@4101 cda61777-01e9-0310-a592-d414129be87e

diff --git a/bk_pdf.c b/bk_pdf.c
index e9904e7..fa5262a 100644 (file)
--- a/bk_pdf.c
+++ b/bk_pdf.c
@@ -35,6 +35,8 @@ static void objtext(object *o, char const *text);
 static void objstream(object *o, char const *text);
 static void pdf_string(void (*add)(object *, char const *),
                       object *, char const *);
+static void pdf_string_len(void (*add)(object *, char const *),
+                          object *, char const *, int);
 static void objref(object *o, object *dest);
 
 static void make_pages_node(object *node, object *parent, page_data *first,
@@ -580,44 +582,32 @@ static void make_pages_node(object *node, object *parent, page_data *first,
  * means that glyphs are identified by PS strings and hence font
  * encoding can be managed independently of the supplied encoding
  * of the font. However, in the document outline, the PDF spec
- * simply asks for ordinary text strings without mentioning what
- * character set they are supposed to be interpreted in.
- * 
- * Therefore, for the moment, I'm going to assume they're US-ASCII
- * only. If anyone knows better, they should let me know :-/
+ * encodes in either PDFDocEncoding (a custom superset of
+ * ISO-8859-1) or UTF-16BE.
  */
-static int pdf_convert(wchar_t *s, char **result) {
-    int doing = (result != 0);
-    int ok = TRUE;
-    char *p = NULL;
-    int plen = 0, psize = 0;
-
-    for (; *s; s++) {
-       wchar_t c = *s;
-       char outc;
-
-       if (c >= 32 && c <= 126) {
-           /* Char is OK. */
-           outc = (char)c;
-       } else {
-           /* Char is not OK. */
-           ok = FALSE;
-           outc = 0xBF;               /* approximate the good old DEC `uh?' */
-       }
-       if (doing) {
-           if (plen >= psize) {
-               psize = plen + 256;
-               p = resize(p, psize);
-           }
-           p[plen++] = outc;
-       }
+static char *pdf_outline_convert(wchar_t *s, int *len) {
+    char *ret;
+
+    ret = utoa_careful_dup(s, CS_PDF);
+
+    /*
+     * Very silly special case: if the returned string begins with
+     * FE FF, then the PDF reader will mistake it for a UTF-16BE
+     * string. So in this case we give up on PDFDocEncoding and
+     * encode it in UTF-16 straight away.
+     */
+    if (ret && ret[0] == '\xFE' && ret[1] == '\xFF') {
+       sfree(ret);
+       ret = NULL;
     }
-    if (doing) {
-       p = resize(p, plen+1);
-       p[plen] = '\0';
-       *result = p;
+
+    if (!ret) {
+       ret = utoa_dup_len(s, CS_UTF16BE, len);
+    } else {
+       *len = strlen(ret);
     }
-    return ok;
+
+    return ret;
 }
 
 static int make_outline(object *parent, outline_element *items, int n,
@@ -633,6 +623,7 @@ static int make_outline(object *parent, outline_element *items, int n,
 
     while (n > 0) {
        char *title;
+       int titlelen;
 
        /*
         * Here we expect to be sitting on an item at the given
@@ -641,14 +632,14 @@ static int make_outline(object *parent, outline_element *items, int n,
         */
        assert(items->level == level);
 
-       pdf_convert(items->pdata->outline_title, &title);
+       title = pdf_outline_convert(items->pdata->outline_title, &titlelen);
 
        totalcount++;
        curr = new_object(parent->list);
        if (!first) first = curr;
        last = curr;
        objtext(curr, "<<\n/Title ");
-       pdf_string(objtext, curr, title);
+       pdf_string_len(objtext, curr, title, titlelen);
        objtext(curr, "\n/Parent ");
        objref(curr, parent);
        objtext(curr, "\n/Dest [");
@@ -739,19 +730,30 @@ static int pdf_versionid(FILE *fp, word *words)
     return ret;
 }
 
-static void pdf_string(void (*add)(object *, char const *),
-                      object *o, char const *str)
+static void pdf_string_len(void (*add)(object *, char const *),
+                          object *o, char const *str, int len)
 {
     char const *p;
 
     add(o, "(");
-    for (p = str; *p; p++) {
-       char c[2];
-       if (*p == '\\' || *p == '(' || *p == ')')
-           add(o, "\\");
-       c[0] = *p;
-       c[1] = '\0';
+    for (p = str; len > 0; p++, len--) {
+       char c[10];
+       if (*p < ' ' || *p > '~') {
+           sprintf(c, "\\%03o", 0xFF & (int)*p);
+       } else {
+           int n = 0;
+           if (*p == '\\' || *p == '(' || *p == ')')
+               c[n++] = '\\';
+           c[n++] = *p;
+           c[n] = '\0';
+       }
        add(o, c);
     }
     add(o, ")");
 }
+
+static void pdf_string(void (*add)(object *, char const *),
+                      object *o, char const *str)
+{
+    pdf_string_len(add, o, str, strlen(str));
+}