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author | Paul Eggert <eggert@cs.ucla.edu> | 2019-06-25 15:54:37 -0700 |
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committer | Paul Eggert <eggert@cs.ucla.edu> | 2019-06-25 15:56:58 -0700 |
commit | 824f78418783ee0af1c804b0decb037a13a4365e (patch) | |
tree | 7a4127256fa1117b609b1d5c50c8490b391708e1 /lib-src | |
parent | 7dcefa7a2bb4d2531d23cbf51eb98ce7727b366c (diff) | |
download | emacs-824f78418783ee0af1c804b0decb037a13a4365e.tar.gz |
Prefer PATH_MAX to MAXPATHLEN
PATH_MAX is standardized, MAXPATHLEN is not.
Also, the Gnulib pathmax module fixes some rare bugs with PATH_MAX.
So prefer PATH_MAX to MAXPATHLEN unless we know the latter is
also correct (for some platform-specific code).
* admin/merge-gnulib (GNULIB_MODULES): Add pathmax.
This module was already present, as a dependency of canonicalize-lgpl,
but now Emacs is using it directly. Sort.
* lib-src/emacsclient.c: Include stdint.h, pathmax.h.
(get_current_dir_name): Sync to current src/sysdep.c.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* src/sysdep.c: Include pathmax.h.
(get_current_dir_name_or_unreachable):
Use PATH_MAX instead of MAXPATHLEN.
Diffstat (limited to 'lib-src')
-rw-r--r-- | lib-src/emacsclient.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/lib-src/emacsclient.c b/lib-src/emacsclient.c index 4da532b42de..6c806fb5830 100644 --- a/lib-src/emacsclient.c +++ b/lib-src/emacsclient.c @@ -74,6 +74,7 @@ char *w32_getenv (const char *); #include <signal.h> #include <stdarg.h> #include <stddef.h> +#include <stdint.h> #include <stdlib.h> #include <string.h> #include <sys/stat.h> @@ -82,6 +83,7 @@ char *w32_getenv (const char *); #include <dosname.h> #include <intprops.h> #include <min-max.h> +#include <pathmax.h> #include <unlocked-io.h> /* Work around GCC bug 88251. */ @@ -238,6 +240,17 @@ char *get_current_dir_name (void); char * get_current_dir_name (void) { + /* The maximum size of a directory name, including the terminating NUL. + Leave room so that the caller can append a trailing slash. */ + ptrdiff_t dirsize_max = min (PTRDIFF_MAX, SIZE_MAX) - 1; + + /* The maximum size of a buffer for a file name, including the + terminating NUL. This is bounded by PATH_MAX, if available. */ + ptrdiff_t bufsize_max = dirsize_max; +#ifdef PATH_MAX + bufsize_max = min (bufsize_max, PATH_MAX); +#endif + char *buf; struct stat dotstat, pwdstat; /* If PWD is accurate, use it instead of calling getcwd. PWD is @@ -245,15 +258,12 @@ get_current_dir_name (void) parent directory is searchable but not readable. */ char const *pwd = egetenv ("PWD"); if (pwd - && (IS_DIRECTORY_SEP (*pwd) || (*pwd && IS_DEVICE_SEP (pwd[1]))) + && (pwdlen = strnlen (pwd, bufsize_max)) < bufsize_max + && IS_DIRECTORY_SEP (pwd[pwdlen && IS_DEVICE_SEP (pwd[1]) ? 2 : 0]) && stat (pwd, &pwdstat) == 0 && stat (".", &dotstat) == 0 && dotstat.st_ino == pwdstat.st_ino - && dotstat.st_dev == pwdstat.st_dev -# ifdef MAXPATHLEN - && strlen (pwd) < MAXPATHLEN -# endif - ) + && dotstat.st_dev == pwdstat.st_dev) { buf = xmalloc (strlen (pwd) + 1); strcpy (buf, pwd); |