diff options
Diffstat (limited to 'src/print.c')
| -rw-r--r-- | src/print.c | 34 |
1 files changed, 28 insertions, 6 deletions
diff --git a/src/print.c b/src/print.c index 80fe22c7149..1cc85270bc6 100644 --- a/src/print.c +++ b/src/print.c @@ -365,7 +365,10 @@ printchar (ch, fun) print_buffer. PRINTCHARFUN t means output to the echo area or to stdout if non-interactive. If neither nil nor t, call Lisp function PRINTCHARFUN for each character printed. MULTIBYTE - non-zero means PTR contains multibyte characters. */ + non-zero means PTR contains multibyte characters. + + In the case where PRINTCHARFUN is nil, it is safe for PTR to point + to data in a Lisp string. Otherwise that is not safe. */ static void strout (ptr, size, size_byte, printcharfun, multibyte) @@ -414,7 +417,7 @@ strout (ptr, size, size_byte, printcharfun, multibyte) if (size == size_byte) { for (i = 0; i < size; ++i) - insert_char ((unsigned char )*ptr++); + insert_char ((unsigned char) *ptr++); } else { @@ -502,10 +505,29 @@ print_string (string, printcharfun) else chars = SBYTES (string); - /* strout is safe for output to a frame (echo area) or to print_buffer. */ - strout (SDATA (string), - chars, SBYTES (string), - printcharfun, STRING_MULTIBYTE (string)); + if (EQ (printcharfun, Qt)) + { + /* Output to echo area. */ + int nbytes = SBYTES (string); + char *buffer; + + /* Copy the string contents so that relocation of STRING by + GC does not cause trouble. */ + USE_SAFE_ALLOCA; + + SAFE_ALLOCA (buffer, char *, nbytes); + bcopy (SDATA (string), buffer, nbytes); + + strout (buffer, chars, SBYTES (string), + printcharfun, STRING_MULTIBYTE (string)); + + SAFE_FREE (); + } + else + /* No need to copy, since output to print_buffer can't GC. */ + strout (SDATA (string), + chars, SBYTES (string), + printcharfun, STRING_MULTIBYTE (string)); } else { |