Make CMap parser more robust.

If an error is encountered, skip ahead to the next matching "endxxx"
keyword, or to the next error, or to the end of file.

diff --git a/source/pdf/pdf-cmap-parse.c b/source/pdf/pdf-cmap-parse.c
index 1ff894cf054b1b16c2aaf451fb7f708b295d5a85..07881da5a1ac3bfe3419a1dd75e9eb8decee2685 100644 (file)
--- a/source/pdf/pdf-cmap-parse.c
+++ b/source/pdf/pdf-cmap-parse.c
@@ -29,6 +29,45 @@
  * CMap parser
  */
 
+static int
+is_keyword(pdf_token tok, pdf_lexbuf *buf, const char *word)
+{
+       /* Ignore trailing garbage when matching keywords */
+       return (tok == PDF_TOK_KEYWORD && !strncmp(buf->scratch, word, strlen(word)));
+}
+
+static void
+skip_to_keyword(fz_context *ctx, fz_stream *file, pdf_lexbuf *buf, const char *end, const char *warn)
+{
+       fz_warn(ctx, "%s", warn);
+       for (;;)
+       {
+               pdf_token tok = pdf_lex(ctx, file, buf);
+               if (is_keyword(tok, buf, end))
+                       return;
+               if (tok == PDF_TOK_ERROR)
+                       return;
+               if (tok == PDF_TOK_EOF)
+                       return;
+       }
+}
+
+static void
+skip_to_token(fz_context *ctx, fz_stream *file, pdf_lexbuf *buf, pdf_token end, const char *warn)
+{
+       fz_warn(ctx, "%s", warn);
+       for (;;)
+       {
+               pdf_token tok = pdf_lex(ctx, file, buf);
+               if (tok == end)
+                       return;
+               if (tok == PDF_TOK_ERROR)
+                       return;
+               if (tok == PDF_TOK_EOF)
+                       return;
+       }
+}
+
 static int
 pdf_code_from_string(char *buf, size_t len)
 {
@@ -64,13 +103,6 @@ pdf_parse_wmode(fz_context *ctx, pdf_cmap *cmap, fz_stream *file, pdf_lexbuf *bu
                fz_warn(ctx, "expected integer after WMode in cmap");
 }
 
-static int
-is_keyword(pdf_token tok, pdf_lexbuf *buf, const char *word)
-{
-       /* Ignore trailing garbage when matching keywords */
-       return (tok == PDF_TOK_KEYWORD && !strncmp(buf->scratch, word, strlen(word)));
-}
-
 static void
 pdf_parse_codespace_range(fz_context *ctx, pdf_cmap *cmap, fz_stream *file, pdf_lexbuf *buf)
 {
@@ -93,13 +125,18 @@ pdf_parse_codespace_range(fz_context *ctx, pdf_cmap *cmap, fz_stream *file, pdf_
                                hi = pdf_code_from_string(buf->scratch, buf->len);
                                pdf_add_codespace(ctx, cmap, lo, hi, buf->len);
                        }
-                       else break;
+                       else
+                       {
+                               skip_to_keyword(ctx, file, buf, "endcodespacerange", "expected string or endcodespacerange");
+                               return;
+                       }
+               }
+               else
+               {
+                       skip_to_keyword(ctx, file, buf, "endcodespacerange", "expected string or endcodespacerange");
+                       return;
                }
-
-               else break;
        }
-
-       fz_throw(ctx, FZ_ERROR_GENERIC, "expected string or endcodespacerange");
 }
 
 static void
@@ -116,19 +153,28 @@ pdf_parse_cid_range(fz_context *ctx, pdf_cmap *cmap, fz_stream *file, pdf_lexbuf
                        return;
 
                else if (tok != PDF_TOK_STRING)
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected string or endcidrange");
+               {
+                       skip_to_keyword(ctx, file, buf, "endcidrange", "expected string or endcidrange");
+                       return;
+               }
 
                lo = pdf_code_from_string(buf->scratch, buf->len);
 
                tok = pdf_lex(ctx, file, buf);
                if (tok != PDF_TOK_STRING)
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected string");
+               {
+                       skip_to_keyword(ctx, file, buf, "endcidrange", "expected string");
+                       return;
+               }
 
                hi = pdf_code_from_string(buf->scratch, buf->len);
 
                tok = pdf_lex(ctx, file, buf);
                if (tok != PDF_TOK_INT)
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected integer");
+               {
+                       skip_to_keyword(ctx, file, buf, "endcidrange", "expected integer");
+                       return;
+               }
 
                dst = buf->i;
 
@@ -150,13 +196,19 @@ pdf_parse_cid_char(fz_context *ctx, pdf_cmap *cmap, fz_stream *file, pdf_lexbuf
                        return;
 
                else if (tok != PDF_TOK_STRING)
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected string or endcidchar");
+               {
+                       skip_to_keyword(ctx, file, buf, "endcidchar", "expected string or endcidchar");
+                       return;
+               }
 
                src = pdf_code_from_string(buf->scratch, buf->len);
 
                tok = pdf_lex(ctx, file, buf);
                if (tok != PDF_TOK_INT)
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected integer");
+               {
+                       skip_to_keyword(ctx, file, buf, "endcidchar", "expected integer");
+                       return;
+               }
 
                dst = buf->i;
 
@@ -179,7 +231,10 @@ pdf_parse_bf_range_array(fz_context *ctx, pdf_cmap *cmap, fz_stream *file, pdf_l
 
                /* Note: does not handle [ /Name /Name ... ] */
                else if (tok != PDF_TOK_STRING)
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected string or ]");
+               {
+                       skip_to_token(ctx, file, buf, PDF_TOK_CLOSE_ARRAY, "expected string or ]");
+                       return;
+               }
 
                if (buf->len / 2)
                {
@@ -209,18 +264,24 @@ pdf_parse_bf_range(fz_context *ctx, pdf_cmap *cmap, fz_stream *file, pdf_lexbuf
                        return;
 
                else if (tok != PDF_TOK_STRING)
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected string or endbfrange");
+               {
+                       skip_to_keyword(ctx, file, buf, "endbfrange", "expected string or endbfrange");
+                       return;
+               }
 
                lo = pdf_code_from_string(buf->scratch, buf->len);
 
                tok = pdf_lex(ctx, file, buf);
                if (tok != PDF_TOK_STRING)
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected string");
+               {
+                       skip_to_keyword(ctx, file, buf, "endbfrange", "expected string");
+                       return;
+               }
 
                hi = pdf_code_from_string(buf->scratch, buf->len);
                if (lo < 0 || lo > 65535 || hi < 0 || hi > 65535 || lo > hi)
                {
-                       fz_warn(ctx, "bf_range limits out of range in cmap %s", cmap->cmap_name);
+                       skip_to_keyword(ctx, file, buf, "endbfrange", "bfrange limits out of range");
                        return;
                }
 
@@ -261,7 +322,8 @@ pdf_parse_bf_range(fz_context *ctx, pdf_cmap *cmap, fz_stream *file, pdf_lexbuf
 
                else
                {
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected string or array or endbfrange");
+                       skip_to_keyword(ctx, file, buf, "endbfrange", "expected string or array or endbfrange");
+                       return;
                }
        }
 }
@@ -281,14 +343,20 @@ pdf_parse_bf_char(fz_context *ctx, pdf_cmap *cmap, fz_stream *file, pdf_lexbuf *
                        return;
 
                else if (tok != PDF_TOK_STRING)
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected string or endbfchar");
+               {
+                       skip_to_keyword(ctx, file, buf, "endbfchar", "expected string or endbfchar");
+                       return;
+               }
 
                src = pdf_code_from_string(buf->scratch, buf->len);
 
                tok = pdf_lex(ctx, file, buf);
                /* Note: does not handle /dstName */
                if (tok != PDF_TOK_STRING)
-                       fz_throw(ctx, FZ_ERROR_GENERIC, "expected string");
+               {
+                       skip_to_keyword(ctx, file, buf, "endbfchar", "expected string");
+                       return;
+               }
 
                if (buf->len / 2)
                {