dovecot-2.2: lib-mail: message_header_encode_[bq]() now explicit...

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-2.2/rev/009caac530e9
changeset: 17367:009caac530e9
user:      Timo Sirainen <tss at iki.fi>
date:      Sun May 11 21:08:51 2014 +0300
description:
lib-mail: message_header_encode_[bq]() now explicitly takes the first line length parameter.
So this change partially reverts the previous change, because
message_header_encode() was actually internally relying on this behavior.
The explicit parameter makes it clearer.

diffstat:

 src/lib-mail/message-header-encode.c      |  37 ++++++++++++++++++++++--------
 src/lib-mail/message-header-encode.h      |  10 +++++---
 src/lib-mail/test-message-header-encode.c |   6 +++-
 3 files changed, 37 insertions(+), 16 deletions(-)

diffs (123 lines):

diff -r 4892a941d63b -r 009caac530e9 src/lib-mail/message-header-encode.c
--- a/src/lib-mail/message-header-encode.c	Sun May 11 18:28:03 2014 +0300
+++ b/src/lib-mail/message-header-encode.c	Sun May 11 21:08:51 2014 +0300
@@ -29,12 +29,20 @@
 }
 
 void message_header_encode_q(const unsigned char *input, unsigned int len,
-			     string_t *output)
+			     string_t *output, unsigned int first_line_len)
 {
 	unsigned int i, line_len_left;
 
+	line_len_left = MIME_MAX_LINE_LEN - MIME_WRAPPER_LEN;
+
+	if (first_line_len >= MIME_MAX_LINE_LEN - MIME_WRAPPER_LEN - 3) {
+		str_append(output, "\n\t");
+		line_len_left--;
+	} else {
+		line_len_left -= first_line_len;
+	}
+
 	str_append(output, "=?utf-8?q?");
-	line_len_left = MIME_MAX_LINE_LEN - MIME_WRAPPER_LEN;
 	for (i = 0; i < len; i++) {
 		if (line_len_left < 3) {
 			/* if we're not at the beginning of a character,
@@ -72,12 +80,18 @@
 }
 
 void message_header_encode_b(const unsigned char *input, unsigned int len,
-			     string_t *output)
+			     string_t *output, unsigned int first_line_len)
 {
-	unsigned int line_len_left, max;
+	unsigned int line_len, line_len_left, max;
 
-	line_len_left = MIME_MAX_LINE_LEN - MIME_WRAPPER_LEN;
+	line_len = first_line_len;
+	if (line_len >= MIME_MAX_LINE_LEN - MIME_WRAPPER_LEN) {
+		str_append(output, "\n\t");
+		line_len = 1;
+	}
+
 	for (;;) {
+		line_len_left = MIME_MAX_LINE_LEN - MIME_WRAPPER_LEN - line_len;
 		max = MAX_BASE64_DECODED_SIZE(line_len_left);
 		do {
 			max--;
@@ -105,7 +119,7 @@
 			break;
 
 		str_append(output, "\n\t");
-		line_len_left = MIME_MAX_LINE_LEN - MIME_WRAPPER_LEN - 1;
+		line_len = 1;
 	}
 }
 
@@ -155,9 +169,12 @@
 
 	/* and do it */
 	str_append_data(output, input, first_idx);
-	if (use_q)
-		message_header_encode_q(input + first_idx, enc_len, output);
-	else
-		message_header_encode_b(input + first_idx, enc_len, output);
+	if (use_q) {
+		message_header_encode_q(input + first_idx, enc_len,
+					output, first_idx);
+	} else {
+		message_header_encode_b(input + first_idx, enc_len,
+					output, first_idx);
+	}
 	str_append_data(output, input + last_idx, len - last_idx);
 }
diff -r 4892a941d63b -r 009caac530e9 src/lib-mail/message-header-encode.h
--- a/src/lib-mail/message-header-encode.h	Sun May 11 18:28:03 2014 +0300
+++ b/src/lib-mail/message-header-encode.h	Sun May 11 21:08:51 2014 +0300
@@ -1,16 +1,18 @@
 #ifndef MESSAGE_HEADER_ENCODE_H
 #define MESSAGE_HEADER_ENCODE_H
 
-/* Encode UTF-8 input into output wherever necessary. */
+/* Encode UTF-8 input into output wherever necessary using either Q or B
+   encoding depending on which takes less space (approximately). */
 void message_header_encode(const char *input, string_t *output);
 void message_header_encode_data(const unsigned char *input, unsigned int len,
 				string_t *output);
 
 /* Encode the whole UTF-8 input using "Q" or "B" encoding into output.
-   The output is split into multiple lines if necessary (max 76 chars/line). */
+   The output is split into multiple lines if necessary (max 76 chars/line).
+   The first line's length is given as parameter. */
 void message_header_encode_q(const unsigned char *input, unsigned int len,
-			     string_t *output);
+			     string_t *output, unsigned int first_line_len);
 void message_header_encode_b(const unsigned char *input, unsigned int len,
-			     string_t *output);
+			     string_t *output, unsigned int first_line_len);
 
 #endif
diff -r 4892a941d63b -r 009caac530e9 src/lib-mail/test-message-header-encode.c
--- a/src/lib-mail/test-message-header-encode.c	Sun May 11 18:28:03 2014 +0300
+++ b/src/lib-mail/test-message-header-encode.c	Sun May 11 21:08:51 2014 +0300
@@ -67,7 +67,8 @@
 				str_append_c(str, ' ');
 
 			message_header_encode_q(str_data(input) + skip,
-						str_len(input) - skip, str);
+						str_len(input) - skip, str,
+						i == 0 ? 0 : i+1);
 			test_assert(verify_q(str_c(str), i, !skip));
 		}
 	}
@@ -153,7 +154,8 @@
 				str_append_c(str, ' ');
 
 			message_header_encode_b(str_data(input) + skip,
-						str_len(input) - skip, str);
+						str_len(input) - skip, str,
+						i == 0 ? 0 : i+1);
 			test_assert(verify_b(str_c(str), i, !skip));
 		}
 	}