From 62260ab56e398aba81fef1a3b6d5f72d6aa6532d Mon Sep 17 00:00:00 2001 From: M Stoeckl Date: Sat, 19 Jan 2019 10:31:55 -0500 Subject: [PATCH] Fix backup methods in get_socketpath for IPC client Previously, the success of `getline` was tested by checking if the buffer it allocates is nonempty and has a nonzero first byte. As `getline` does not explicitly zero out its memory buffer, this may fail (e.g., with AddressSanitizer). Instead, we check that at least one character was returned on standard output. Also, trailing newlines (if present) are now removed. --- common/ipc-client.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/common/ipc-client.c b/common/ipc-client.c index 1e88e71f..79ed3555 100644 --- a/common/ipc-client.c +++ b/common/ipc-client.c @@ -22,9 +22,13 @@ char *get_socketpath(void) { size_t line_size = 0; FILE *fp = popen("sway --get-socketpath 2>/dev/null", "r"); if (fp) { - getline(&line, &line_size, fp); + ssize_t nret = getline(&line, &line_size, fp); pclose(fp); - if (line && *line) { + if (nret > 0) { + // remove trailing newline, if there is one + if (line[nret - 1] == '\n') { + line[nret - 1] = '\0'; + } return line; } } @@ -35,9 +39,13 @@ char *get_socketpath(void) { } fp = popen("i3 --get-socketpath 2>/dev/null", "r"); if (fp) { - getline(&line, &line_size, fp); + ssize_t nret = getline(&line, &line_size, fp); pclose(fp); - if (line && *line) { + if (nret > 0) { + // remove trailing newline, if there is one + if (line[nret - 1] == '\n') { + line[nret - 1] = '\0'; + } return line; } }