Don't pass char to <ctype.h> function.

* parser.c (provide_completions): Cast char argument to
unsigned char in call to isalnum. The data comes from
user input, which could be any byte. The char type may be
signed (and usually is) and so may take on negative values.

1 files changed, 4 insertions, 2 deletions

diff --git a/parser.c b/parser.c
index c6f030f8..82cdaa21 100644
--- a/parser.c
+++ b/parser.c
@@ -430,7 +430,8 @@ static void provide_completions(const char *data,
   if (!ptr)
     return;
 
-  while ((isalnum(*ptr) || strchr(gly, *ptr)) && (sym = ptr) && ptr > data)
+  while ((isalnum((unsigned char) *ptr) || strchr(gly, *ptr)) &&
+         (sym = ptr) && ptr > data)
     ptr--;
 
   if (!sym)
@@ -444,7 +445,8 @@ static void provide_completions(const char *data,
     } else {
       ptr--;
 
-      while ((isalnum(*ptr) || strchr(gly, *ptr)) && (pkg = ptr) && ptr > data)
+      while ((isalnum((unsigned char) *ptr) || strchr(gly, *ptr)) &&
+             (pkg = ptr) && ptr > data)
         ptr--;
 
       if (!pkg)