xdiff: cast arguments for ctype functions to unsigned char

The ctype functions isspace(), isalnum(), et al take an integer
argument representing an unsigned character, or -1 for EOF.  On
platforms with a signed char, it is unsafe to pass a char to them
without casting it to unsigned char first.

Most of git is already shielded against this by the ctype
implementation in git-compat-util.h, but xdiff, which uses libc
ctype.h, ought to be fixed.

Noticed-by: der Mouse <mouse@Rodents-Montreal.ORG>
Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/xdiff/xmacros.h b/xdiff/xmacros.h
index 8ef232cfad12d706aaafe705bf16c546f3597182..165a895a93e04b33ca7c8f3839ee85e0eccb4a07 100644 (file)
--- a/xdiff/xmacros.h
+++ b/xdiff/xmacros.h
@@ -30,6 +30,7 @@
 #define XDL_MAX(a, b) ((a) > (b) ? (a): (b))
 #define XDL_ABS(v) ((v) >= 0 ? (v): -(v))
 #define XDL_ISDIGIT(c) ((c) >= '0' && (c) <= '9')
+#define XDL_ISSPACE(c) (isspace((unsigned char)(c)))
 #define XDL_ADDBITS(v,b)       ((v) + ((v) >> (b)))
 #define XDL_MASKBITS(b)                ((1UL << (b)) - 1)
 #define XDL_HASHLONG(v,b)      (XDL_ADDBITS((unsigned long)(v), b) & XDL_MASKBITS(b))

diff --git a/xdiff/xmerge.c b/xdiff/xmerge.c
index 6d6fc1bc5e01be7305ec5101f43645a1dce69bd3..9e13b25abc90350de4488276074dc282edc216b1 100644 (file)
--- a/xdiff/xmerge.c
+++ b/xdiff/xmerge.c
@@ -336,7 +336,7 @@ static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
 static int line_contains_alnum(const char *ptr, long size)
 {
        while (size--)
-               if (isalnum(*(ptr++)))
+               if (isalnum((unsigned char)*(ptr++)))
                        return 1;
        return 0;
 }

diff --git a/xdiff/xutils.c b/xdiff/xutils.c
index 22f9bd692c2706136b4938bbcb2e0fc3dab212b8..ab6503460f760356a393a3c7b3b8438213e1ee94 100644 (file)
--- a/xdiff/xutils.c
+++ b/xdiff/xutils.c
@@ -211,18 +211,18 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
                        if (l1[i1++] != l2[i2++])
                                return 0;
                skip_ws:
-                       while (i1 < s1 && isspace(l1[i1]))
+                       while (i1 < s1 && XDL_ISSPACE(l1[i1]))
                                i1++;
-                       while (i2 < s2 && isspace(l2[i2]))
+                       while (i2 < s2 && XDL_ISSPACE(l2[i2]))
                                i2++;
                }
        } else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
                while (i1 < s1 && i2 < s2) {
-                       if (isspace(l1[i1]) && isspace(l2[i2])) {
+                       if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
                                /* Skip matching spaces and try again */
-                               while (i1 < s1 && isspace(l1[i1]))
+                               while (i1 < s1 && XDL_ISSPACE(l1[i1]))
                                        i1++;
-                               while (i2 < s2 && isspace(l2[i2]))
+                               while (i2 < s2 && XDL_ISSPACE(l2[i2]))
                                        i2++;
                                continue;
                        }
@@ -241,13 +241,13 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
         * while there still are characters remaining on both lines.
         */
        if (i1 < s1) {
-               while (i1 < s1 && isspace(l1[i1]))
+               while (i1 < s1 && XDL_ISSPACE(l1[i1]))
                        i1++;
                if (s1 != i1)
                        return 0;
        }
        if (i2 < s2) {
-               while (i2 < s2 && isspace(l2[i2]))
+               while (i2 < s2 && XDL_ISSPACE(l2[i2]))
                        i2++;
                return (s2 == i2);
        }
@@ -260,10 +260,10 @@ static unsigned long xdl_hash_record_with_whitespace(char const **data,
        char const *ptr = *data;
 
        for (; ptr < top && *ptr != '\n'; ptr++) {
-               if (isspace(*ptr)) {
+               if (XDL_ISSPACE(*ptr)) {
                        const char *ptr2 = ptr;
                        int at_eol;
-                       while (ptr + 1 < top && isspace(ptr[1])
+                       while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
                                        && ptr[1] != '\n')
                                ptr++;
                        at_eol = (top <= ptr + 1 || ptr[1] == '\n');