sucess -> success, failiure -> failure

src/common.cpp

@@ -500,7 +500,7 @@ void append_formatv(wcstring &target, const wchar_t *format, va_list va_orig) {
     // formated string option or because the supplied destination string was to small. In GLIBC,
     // errno seems to be set to EINVAL either way.
     //
-    // Because of this, on failiure we try to increase the buffer size until the free space is
+    // Because of this, on failure we try to increase the buffer size until the free space is
     // larger than max_size, at which point it will conclude that the error was probably due to a
     // badly formated string option, and return an error. Make sure to null terminate string before
     // that, though.

src/parse_execution.cpp

@@ -299,7 +299,7 @@ parse_execution_result_t parse_execution_context_t::run_if_statement(
         }
         parser->pop_block(ib);
     } else {
-        // No job list means no sucessful conditions, so return 0 (issue #1443).
+        // No job list means no successful conditions, so return 0 (issue #1443).
         parser->set_last_statuses(statuses_t::just(STATUS_CMD_OK));
     }
 

src/postfork.cpp

@@ -40,7 +40,7 @@
 
 /// Called only by the child to set its own process group (possibly creating a new group in the
 /// process if it is the first in a JOB_CONTROL job.
-/// Returns true on sucess, false on failiure.
+/// Returns true on success, false on failure.
 bool child_set_group(job_t *j, process_t *p) {
     if (j->wants_job_control()) {
         if (j->pgid == INVALID_PID) {

src/postfork.h

@@ -29,7 +29,7 @@ bool child_set_group(job_t *j, process_t *p);     // called by child
 ///
 /// Assign the terminal to new_termowner unless it is INVALID_PID.
 ///
-/// \return 0 on sucess, -1 on failiure. When this function returns, signals are always unblocked.
+/// \return 0 on success, -1 on failure. When this function returns, signals are always unblocked.
 /// On failure, signal handlers, io redirections and process group of the process is undefined.
 int child_setup_process(pid_t new_termowner, bool is_forked, const dup2_list_t &dup2s);