Issue #5341: Fix a variety of spelling errors.
diff --git a/Objects/abstract.c b/Objects/abstract.c
index ee744de..c67581e 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -2258,7 +2258,7 @@
 
 /* Iterate over seq.  Result depends on the operation:
    PY_ITERSEARCH_COUNT:  -1 if error, else # of times obj appears in seq.
-   PY_ITERSEARCH_INDEX:  0-based index of first occurence of obj in seq;
+   PY_ITERSEARCH_INDEX:  0-based index of first occurrence of obj in seq;
    	set ValueError and return -1 if none found; also return -1 on error.
    Py_ITERSEARCH_CONTAINS:  return 1 if obj in seq, else 0; -1 on error.
 */
diff --git a/Objects/listsort.txt b/Objects/listsort.txt
index 9226984..31a5445 100644
--- a/Objects/listsort.txt
+++ b/Objects/listsort.txt
@@ -309,7 +309,7 @@
     A:10000  B:20000  C:10000
 
 we dare not merge A with C first, because if A, B and C happen to contain
-a common element, it would get out of order wrt its occurence(s) in B.  The
+a common element, it would get out of order wrt its occurrence(s) in B.  The
 merging must be done as (A+B)+C or A+(B+C) instead.
 
 So merging is always done on two consecutive runs at a time, and in-place,
diff --git a/Objects/object.c b/Objects/object.c
index 5dff385..69fb6de 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -1964,7 +1964,7 @@
 none_dealloc(PyObject* ignore)
 {
 	/* This should never get called, but we also don't want to SEGV if
-	 * we accidently decref None out of existance.
+	 * we accidentally decref None out of existence.
 	 */
 	Py_FatalError("deallocating None");
 }
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 1b36a56..03bccaf 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -1704,7 +1704,7 @@
                 charsleft = (charsleft << 16) | ch;
                 /* out, charsleft, bitsleft = */ ENCODE(out, charsleft, bitsleft);
 
-                /* If the next character is special then we dont' need to terminate
+                /* If the next character is special then we don't need to terminate
                    the shift sequence. If the next character is not a BASE64 character
                    or '-' then the shift sequence will be terminated implicitly and we
                    don't have to insert a '-'. */