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Document css_inplace_decode().

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This commit is contained in:
ivanr 2008-09-10 12:44:41 +00:00
parent 2f7ff8f7ab
commit 2ee69ce468
1 changed files with 42 additions and 17 deletions
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59
apache2/msc_util.c
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@ -1203,7 +1203,8 @@ char *resolve_relative_path(apr_pool_t *pool, const char *parent_filename, const
} }
/** /**
* * Decode a string that contains CSS-escaped characters.
*
* References: * References:
* http://www.w3.org/TR/REC-CSS2/syndata.html#q4 * http://www.w3.org/TR/REC-CSS2/syndata.html#q4
* http://www.unicode.org/roadmaps/ * http://www.unicode.org/roadmaps/
@ -1216,38 +1217,53 @@ int css_decode_inplace(unsigned char *input, long int input_len) {
i = count = 0; i = count = 0;
while (i < input_len) { while (i < input_len) {
/* Is the character a backslash? */
if (input[i] == '\\') { if (input[i] == '\\') {
/* Is there at least one more byte? */ /* Is there at least one more byte? */
if (i + 1 < input_len) { if (i + 1 < input_len) {
i++; /* We are not going to need the backslash. */ i++; /* We are not going to need the backslash. */
/* Check for 1-6 hex characters following the backslash */ /* Check for 1-6 hex characters following the backslash */
j = 0; j = 0;
while ((j < 6) && (i + j < input_len) && while ( (j < 6)
(VALID_HEX(input[i + j]))) && (i + j < input_len)
&& (VALID_HEX(input[i + j])))
{ {
j++; j++;
} }
if (j > 0) {
if (j > 0) { /* We have at least one valid hexadecimal character. */
int fullcheck = 0; int fullcheck = 0;
/* For now just use the last two bytes. */ /* For now just use the last two bytes. */
// TODO What do we do if the other bytes are not zeros?
switch (j) { switch (j) {
/* Number of hex characters */ /* Number of hex characters */
case 1: case 1:
*d++ = xsingle2c(&input[i]); *d++ = xsingle2c(&input[i]);
break; break;
case 2: case 2:
case 3: case 3:
/* Use the last two from the end. */
*d++ = x2c(&input[i + j - 2]); *d++ = x2c(&input[i + j - 2]);
break; break;
case 4: case 4:
*d = x2c(&input[i + 2]); /* Use the last two from the end, but request
* a full width check.
*/
*d = x2c(&input[i + j - 2]);
fullcheck = 1; fullcheck = 1;
break; break;
case 5: case 5:
*d = x2c(&input[i + 3]); /* Use the last two from the end, but request
* a full width check if the number is greater
* or equal to 0xFFFF.
*/
*d = x2c(&input[i + j - 2]);
/* Do full check if first byte is 0 */ /* Do full check if first byte is 0 */
if (input[i] == '0') { if (input[i] == '0') {
@ -1257,13 +1273,14 @@ int css_decode_inplace(unsigned char *input, long int input_len) {
d++; d++;
} }
break; break;
case 6: case 6:
*d = x2c(&input[i + 4]); *d = x2c(&input[i + j - 2]);
/* Do full check if first/second bytes are 0 */ /* Do full check if first/second bytes are 0 */
if ((input[i] == '0') && if ( (input[i] == '0')
(input[i + 1] == '0')) && (input[i + 1] == '0')
{ ) {
fullcheck = 1; fullcheck = 1;
} }
else { else {
@ -1272,7 +1289,7 @@ int css_decode_inplace(unsigned char *input, long int input_len) {
break; break;
} }
/* Full width ASCII (ff01 - ff5e) needs 0x20 added */ /* Full width ASCII (0xff01 - 0xff5e) needs 0x20 added */
if (fullcheck) { if (fullcheck) {
if ( (*d > 0x00) && (*d < 0x5f) if ( (*d > 0x00) && (*d < 0x5f)
&& ((input[i + j - 3] == 'f') || && ((input[i + j - 3] == 'f') ||
@ -1296,28 +1313,36 @@ int css_decode_inplace(unsigned char *input, long int input_len) {
i += j; i += j;
} }
/* "\<newline>" must be removed */ /* No hexadecimal digits after backslash */
else if (input[i] == '\n') { else if (input[i] == '\n') {
/* A newline character following backslash is ignored. */
i++; i++;
} }
/* Otherwise we just escape the next character */ /* The character after backslash is not a hexadecimal digit, nor a newline. */
else { else {
/* Use one character after backslash as is. */
*d++ = input[i++]; *d++ = input[i++];
count++; count++;
} }
} }
/* We have a trailing escape */ /* No characters after backslash. */
else { else {
i++; /* Do not include it (continuation to nothing) */ /* Do not include backslash in output (continuation to nothing) */
i++;
} }
} else { }
/* Character is not a backslash. */
else {
/* Copy one normal character to output. */
*d++ = input[i++]; *d++ = input[i++];
count++; count++;
} }
} }
/* Terminate output string. */
*d = '\0'; *d = '\0';
return count; return count;