strtrim: don't move empty string

There were many cases where the string coming in was a blank line, e.g.
"\n\0", length 1. The trim routine starts by trimming leading spaces,
thus trimming everything. We would then proceed to do a memmove of the
NULL byte, which is completely worthless as we can just assign it
instead.

Signed-off-by: Dan McGee <dan@archlinux.org>

3 files changed, 18 insertions, 3 deletions

diff --git a/lib/libalpm/util.c b/lib/libalpm/util.c
index 7e3bc372..cf783893 100644
--- a/lib/libalpm/util.c
+++ b/lib/libalpm/util.c
@@ -192,7 +192,12 @@ char *_alpm_strtrim(char *str)
 		pch++;
 	}
 	if(pch != str) {
-		memmove(str, pch, (strlen(pch) + 1));
+		size_t len = strlen(pch);
+		if(len) {
+			memmove(str, pch, len + 1);
+		} else {
+			*str = '\0';
+		}
 	}
 
 	/* check if there wasn't anything but whitespace in the string. */
diff --git a/src/pacman/util.c b/src/pacman/util.c
index 2de4bd44..cb62ec66 100644
--- a/src/pacman/util.c
+++ b/src/pacman/util.c
@@ -342,7 +342,12 @@ char *strtrim(char *str)
 		pch++;
 	}
 	if(pch != str) {
-		memmove(str, pch, (strlen(pch) + 1));
+		size_t len = strlen(pch);
+		if(len) {
+			memmove(str, pch, len + 1);
+		} else {
+			*str = '\0';
+		}
 	}
 
 	/* check if there wasn't anything but whitespace in the string. */
diff --git a/src/util/pactree.c b/src/util/pactree.c
index 5a27cc77..b8832912 100644
--- a/src/util/pactree.c
+++ b/src/util/pactree.c
@@ -103,7 +103,12 @@ static char *strtrim(char *str)
 		pch++;
 	}
 	if(pch != str) {
-		memmove(str, pch, (strlen(pch) + 1));
+		size_t len = strlen(pch);
+		if(len) {
+			memmove(str, pch, len + 1);
+		} else {
+			*str = '\0';
+		}
 	}
 
 	/* check if there wasn't anything but whitespace in the string. */