atom_explode: be more careful with eating suffix letters

Make sure we don't just eat a char at the end of the atom, because if
that char appears after a -, it will be seen as version part.  An
example is xerces-c, where the parsed atom form would just be xerces.

Bug: https://bugs.gentoo.org/638816

1 files changed, 5 insertions, 2 deletions

diff --git a/libq/atom_explode.c b/libq/atom_explode.c
index 956ac49..057bfa1 100644
--- a/libq/atom_explode.c
+++ b/libq/atom_explode.c
@@ -218,9 +218,12 @@ atom_explode(const char *atom)
 		ret->suffixes[idx] = t;
 	}
 
-	/* allow for 1 optional suffix letter */
+	/* allow for 1 optional suffix letter, must be following a number
+	 * otherwise we eat stuff like -c, see bug #639978 */
 	ptr = ret->PN + strlen(ret->PN);
-	if (ptr[-1] >= 'a' && ptr[-1] <= 'z') {
+	if (ptr[-1] >= 'a' && ptr[-1] <= 'z' &&
+			ptr - 2 > ret->PN && ptr[-2] >= '0' && ptr[-2] <= '9')
+	{
 		ret->letter = ptr[-1];
 		--ptr;
 	}