Add PDFCharIsLineEnding helper

core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp

Index: core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
index 1815d401949ba5aa25ee3b188cc6ea10e84c98da..255d0ce29cade6840340e5ac51253341f1a0985e 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
@@ -80,9 +80,9 @@ FX_DWORD _A85Decode(const uint8_t* src_buf,
   pos = dest_size = 0;
   while (pos < src_size) {
     uint8_t ch = src_buf[pos++];
-    if (ch == '\n' || ch == '\r' || ch == ' ' || ch == '\t') {
+    if (PDFCharIsLineEnding(ch) || ch == ' ' || ch == '\t')

[Tom Sepez, 2015/10/28 17:17:21]

How does this differ from the standard IsWhitespace test?

[dsinclair, 2015/10/28 18:05:07]

std::isspace is more restrictive in that it also checks for \v and \f. I'm not
sure if that's a valid addition to this logic or not.

[dsinclair, 2015/10/28 18:32:06]

For this one, it isn't spec compliant. The PDF spec says:

The ASCII85Decode filter shall ignore
all white-space characters (see 7.2, "Lexical Conventions"). 

Which 7.2 define as:

null 0x00
horizontal tab 0x09
line feed 0x0a
form feed 0x0c
carriage return 0x0d
space    0x20   


The std::isspace includes vertical tab 0x0b which isn't in the list of
whitespace chars in the PDF spec.

       continue;
-    }
+
     if (ch == 'z') {
       FXSYS_memset(dest_buf + dest_size, 0, 4);
       state = 0;
@@ -131,9 +131,9 @@ FX_DWORD _HexDecode(const uint8_t* src_buf,
   FX_BOOL bFirstDigit = TRUE;
   for (i = 0; i < src_size; i++) {
     uint8_t ch = src_buf[i];
-    if (ch == ' ' || ch == '\n' || ch == '\t' || ch == '\r') {
+    if (PDFCharIsLineEnding(ch) || ch == ' ' || ch == '\t')

[Tom Sepez, 2015/10/28 17:17:21]

ditto

[dsinclair, 2015/10/28 18:32:06]

I think this is similar in that PDF doesn't list vertical tab as whitespace in
their spec.

       continue;
-    }
+
     int digit;
     if (ch <= '9' && ch >= '0') {
       digit = ch - '0';