Commit 66f6958e authored Oct 31, 2011 by Michael Holzheu Committed by Linus Torvalds Oct 31, 2011

lib/string.c: fix strim() semantics for strings that have only blanks



Commit 84c95c9a ("string: on strstrip(), first remove leading spaces
before running over str") improved the performance of the strim()
function.

Unfortunately this changed the semantics of strim() and broke my code.
Before the patch it was possible to use strim() without using the return
value for removing trailing spaces from strings that had either only
blanks or only trailing blanks.

Now this does not work any longer for strings that *only* have blanks.

Before patch: "   " -> ""    (empty string)
After patch:  "   " -> "   " (no change)

I think we should remove your patch to restore the old behavior.

The description (lib/string.c):

 * Note that the first trailing whitespace is replaced with a %NUL-terminator

=> The first trailing whitespace of a string that only has whitespace
   characters is the first whitespace

The patch restores the old strim() semantics.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Andre Goddard Rosa <andre.goddard@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e3816c54

lib/string.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -360,7 +360,6 @@ char strim(char s)
		size_t size;
		char *end;

		s = skip_spaces(s);
		size = strlen(s);
		if (!size)
		return s;
		@@ -370,7 +369,7 @@ char strim(char s)
		end--;
		*(end + 1) = '\0';

		return s;
		return skip_spaces(s);
		}
		EXPORT_SYMBOL(strim);

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