* fns.c (Fcompare_strings): Doc fix.

* strings.texi (Text Comparison): Doc fix for compare-strings.

Fixes: debbugs:13081

2 files changed, 16 insertions, 6 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index fe30528da91..c123606efda 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2012-12-15  Chong Yidong  <cyd@gnu.org>
+
+        * fns.c (Fcompare_strings): Doc fix (Bug#13081).
+
 2012-12-14  Eli Zaretskii  <eliz@gnu.org>
 
         * w32.c (get_name_and_id): Always pass NULL as the first argument
diff --git a/src/fns.c b/src/fns.c
index b1ba5ce9509..539e8888dbc 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -211,12 +211,18 @@ Symbols are also allowed; their print names are used instead.  */)
 
 DEFUN ("compare-strings", Fcompare_strings, Scompare_strings, 6, 7, 0,
        doc: /* Compare the contents of two strings, converting to multibyte if needed.
-In string STR1, skip the first START1 characters and stop at END1.
-In string STR2, skip the first START2 characters and stop at END2.
-END1 and END2 default to the full lengths of the respective strings.
-
-Case is significant in this comparison if IGNORE-CASE is nil.
-Unibyte strings are converted to multibyte for comparison.
+The arguments START1, END1, START2, and END2, if non-nil, are
+positions specifying which parts of STR1 or STR2 to compare.  In
+string STR1, compare the part between START1 (inclusive) and END1
+\(exclusive).  If START1 is nil, it defaults to 0, the beginning of
+the string; if END1 is nil, it defaults to the length of the string.
+Likewise, in string STR2, compare the part between START2 and END2.
+
+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
+strings are converted to multibyte for comparison.
 
 The value is t if the strings (or specified portions) match.
 If string STR1 is less, the value is a negative number N;