diff options
Diffstat (limited to 'converter/pbm/pbmtonokia.c')
| -rw-r--r-- | converter/pbm/pbmtonokia.c | 87 |
1 files changed, 54 insertions, 33 deletions
diff --git a/converter/pbm/pbmtonokia.c b/converter/pbm/pbmtonokia.c index 80b0bd59..4604064a 100644 --- a/converter/pbm/pbmtonokia.c +++ b/converter/pbm/pbmtonokia.c @@ -83,7 +83,7 @@ parseCommandLine(int argc, char ** argv, MALLOCARRAY_NOFAIL(option_def, 100); option_def_index = 0; /* incremented by OPTENT3 */ - OPTENT3(0, "fmt", OPT_STRING, &fmtOpt, + OPTENT3(0, "fmt", OPT_STRING, &fmtOpt, &fmtSpec, 0); OPTENT3(0, "net", OPT_STRING, &netOpt, &netSpec, 0); @@ -135,7 +135,7 @@ parseCommandLine(int argc, char ** argv, "the 120 characters allowed by the format.", (unsigned)strlen(cmdlineP->txt)); - if (argc-1 == 0) + if (argc-1 == 0) cmdlineP->inputFileName = "-"; else if (argc-1 != 1) pm_error("Program takes zero or one argument (filename). You " @@ -180,7 +180,7 @@ convertToHexNol(bit ** const image, /* header */ fprintf(ofP, "06050415820000%s00%02X%02X01", networkCode, cols, rows); - + /* image */ for (row = 0; row < rows; ++row) { unsigned int col; @@ -245,7 +245,7 @@ convertToHexNpm(bit ** const image, FILE * const ofP) { unsigned int row; - + /* header */ fprintf(ofP, "060504158A0000"); @@ -293,7 +293,7 @@ convertToNol(bit ** const image, unsigned int row; char header[32]; unsigned int it; - + /* header - this is a hack */ header[ 0] = 'N'; @@ -318,7 +318,7 @@ convertToNol(bit ** const image, header[19] = 0; fwrite(header, 20, 1, ofP); - + /* image */ for (row = 0; row < rows; ++row) { unsigned int col; @@ -368,7 +368,7 @@ convertToNgg(bit ** const image, header[15] = 0; fwrite(header, 16, 1, ofP); - + /* image */ for (row = 0; row < rows; ++row) { @@ -395,35 +395,56 @@ convertToNpm(bit ** const image, const char * const text, FILE * const ofP) { + size_t const textLen = text ? strlen(text) : 0; + unsigned int row; char header[132]; - size_t len; - - if (text) - len = strlen(text); - else - len = 0; /* header and optional text */ - header[ 0] = 'N'; - header[ 1] = 'P'; - header[ 2] = 'M'; - header[ 3] = 0; - header[ 4] = len; - header[ 5] = 0; - if (text) - memcpy(&header[6], text, len); - header[ 6 + len] = cols; - header[ 7 + len] = rows; - header[ 8 + len] = 1; - header[ 9 + len] = 1; - header[10 + len] = 0; /* unknown */ - - assert(10 + len < sizeof(header)); - - fwrite(header, 11 + len, 1, ofP); - + /* Our entry condition is that 'text' be a legal text field, which means + no more than 120 characters: + */ + assert(textLen <= 120); + + /* We don't have any specification of this format, but in May 2020, we + found what looks like a bug: the memcpy of the text field started at + &header[5] (overwriting the previous setting of header[5] and leaving + header[6+len-1] not set to anything). Nobody ever complained about + this, so maybe somehow it worked better than the sensible code we have + now, where the text field starts in the 7th byte. + */ + + /* The code below that deliberately avoids using 'text' as an argument to + memcpy when 'text' is null looks like it should have no practical + effect, because with a zero length memcpy, it shouldn't matter what the + from and to arguments are. But it's logically correct - a null pointer + just doesn't point anywhere. And believe it or not, it has a practical + effect - a truly bizarre one. This code used to be simpler and just + pass that null pointer to memcpy, with length 0, and as reported in May + 2020, a new optimizing compiler caused header[3] to contain random + values. That's right: 3. Skipping that presumed no-op memcpy stopped + the behavior. + */ + + header[ 0] = 'N'; + header[ 1] = 'P'; + header[ 2] = 'M'; + header[ 3] = 0; + header[ 4] = textLen; + header[ 5] = 0; + if (text) /* see above */ + memcpy(&header[6], text, textLen); + header[ 6 + textLen] = cols; + header[ 7 + textLen] = rows; + header[ 8 + textLen] = 1; + header[ 9 + textLen] = 1; + header[10 + textLen] = 0; /* unknown */ + + assert(10 + textLen < sizeof(header)); + + fwrite(header, 11 + textLen, 1, ofP); + /* image: stream of bits, each row padded to a byte boundary inspired by gnokii/common/gsm-filesystems.c */ @@ -453,7 +474,7 @@ convertToNpm(bit ** const image, -int +int main(int argc, char * argv[]) { @@ -521,6 +542,6 @@ Testing: The data was send with EMI/UCP protocol over TCP/IP. - 7.6.2001: tested with Nokia 3210: 72x14 Operator Logo - - 7.6.2001: tested with Nokia 6210: 72x14 Operator Logo and + - 7.6.2001: tested with Nokia 6210: 72x14 Operator Logo and 72x14 Group Graphic */ |