Fix documentation of 'assoc-string' and 'compare-strings'

* src/minibuf.c (Fassoc_string): Clarify how CASE-FOLD affects the
string comparison.  (Bug#23833)
* src/fns.c (Fcompare_strings): Fix the description of how
IGNORE-CASE affects the comparison.

* doc/lispref/strings.texi (Text Comparison): Clarify how
CASE-FOLD affects the string comparison in 'assoc-string'.  Fix
the description of how IGNORE-CASE affects the comparison in
'compare-strings'.

2 files changed, 3 insertions, 3 deletions

diff --git a/src/fns.c b/src/fns.c
index ef6055c17d1..1f1619300de 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -224,7 +224,7 @@ Like in `substring', negative values are counted from the end.
 The strings are compared by the numeric values of their characters.
 For instance, STR1 is "less than" STR2 if its first differing
 character has a smaller numeric value.  If IGNORE-CASE is non-nil,
-characters are converted to lower-case before comparing them.  Unibyte
+characters are converted to upper-case before comparing them.  Unibyte
 strings are converted to multibyte for comparison.
 
 The value is t if the strings (or specified portions) match.
diff --git a/src/minibuf.c b/src/minibuf.c
index d85a7a9b103..3d34635c6c0 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -1817,8 +1817,8 @@ DEFUN ("assoc-string", Fassoc_string, Sassoc_string, 2, 3, 0,
 This returns the first element of LIST whose car matches the string or
 symbol KEY, or nil if no match exists.  When performing the
 comparison, symbols are first converted to strings, and unibyte
-strings to multibyte.  If the optional arg CASE-FOLD is non-nil, case
-is ignored.
+strings to multibyte.  If the optional arg CASE-FOLD is non-nil, both
+KEY and the elements of LIST are upcased for comparison.
 
 Unlike `assoc', KEY can also match an entry in LIST consisting of a
 single string, rather than a cons cell whose car is a string.  */)