Latest patch from vodz. Adds a check for divide by zero in the posix

math suport, cleaner math syntax error checking, moves redundant signal
string tables (from kill and ash) into libbb and provides a few
cleanups elsewhere.


git-svn-id: svn://busybox.net/trunk/busybox@3181 69ca8d6d-28ef-0310-b511-8ec308f3f277

3 files changed, 27 insertions, 12 deletions

diff --git a/libbb/arith.c b/libbb/arith.c
index c7a3cf98b..04c45ec3d 100644
--- a/libbb/arith.c
+++ b/libbb/arith.c
@@ -119,20 +119,26 @@ static short arith_apply(operator op, long *numstack, long **numstackptr)
                 NUMPTR[-1] = (NUMPTR[-1] <= *NUMPTR);
         else if (op == TOK_MUL)
                 NUMPTR[-1] *= *NUMPTR;
-        else if (op == TOK_DIV)
+        else if (op == TOK_DIV) {
+                if(*NUMPTR==0)
+                        return -2;
                 NUMPTR[-1] /= *NUMPTR;
-        else if (op == TOK_REM)
+                }
+        else if (op == TOK_REM) {
+                if(*NUMPTR==0)
+                        return -2;
                 NUMPTR[-1] %= *NUMPTR;
+                }
         else if (op == TOK_ADD)
                 NUMPTR[-1] += *NUMPTR;
         else if (op == TOK_SUB)
                 NUMPTR[-1] -= *NUMPTR;
         }
         return 0;
-err: return(1);
+err: return(-1);
 }
 
-extern long arith (const char *startbuf)
+extern long arith (const char *startbuf, int *errcode)
 {
         register char arithval;
         const char *expr = startbuf;
@@ -142,8 +148,9 @@ extern long arith (const char *startbuf)
         unsigned char prec;
 
         long *numstack, *numstackptr;
-
         operator *stack = alloca(datasizes * sizeof(operator)), *stackptr = stack;
+
+        *errcode = 0;
         numstack = alloca((datasizes/2+1)*sizeof(long)), numstackptr = numstack;
 
         while ((arithval = *expr)) {
@@ -163,7 +170,8 @@ extern long arith (const char *startbuf)
                                 op = *--stackptr;
                                 if (op == TOK_LPAREN)
                                         goto prologue;
-                                if(ARITH_APPLY(op)) goto err;
+                                *errcode = ARITH_APPLY(op);
+                                if(*errcode) return *errcode;
                         }
                         goto err; /* Mismatched parens */
                 } if (arithval == '|') {
@@ -231,17 +239,22 @@ extern long arith (const char *startbuf)
 
                 prec = PREC(op);
                 if (prec != UNARYPREC)
-                        while (stackptr != stack && PREC(stackptr[-1]) >= prec)
-                                if(ARITH_APPLY(*--stackptr)) goto err;
+                        while (stackptr != stack && PREC(stackptr[-1]) >= prec) {
+                                *errcode = ARITH_APPLY(*--stackptr);
+                                if(*errcode) return *errcode;
+                        }
                 *stackptr++ = op;
                 lasttok = op;
 prologue: ++expr;
         } /* yay */
 
-        while (stackptr != stack)
-                if(ARITH_APPLY(*--stackptr)) goto err;
+        while (stackptr != stack) {
+                *errcode = ARITH_APPLY(*--stackptr);
+                if(*errcode) return *errcode;
+        }
         if (numstackptr != numstack+1) {
 err: 
+            *errcode = -1;
             return -1;
          /* NOTREACHED */
         }
diff --git a/libbb/concat_path_file.c b/libbb/concat_path_file.c
index c699a84f7..86dd2fbbf 100644
--- a/libbb/concat_path_file.c
+++ b/libbb/concat_path_file.c
@@ -17,7 +17,7 @@ extern char *concat_path_file(const char *path, const char *filename)
         if (!path)
             path="";
         lc = last_char_is(path, '/');
-        if (filename[0] == '/')
+        while (*filename == '/')
                 filename++;
         outbuf = xmalloc(strlen(path)+strlen(filename)+1+(lc==NULL));
         sprintf(outbuf, "%s%s%s", path, (lc==NULL)? "/" : "", filename);
diff --git a/libbb/libbb.h b/libbb/libbb.h
index 66acc2278..df52027ce 100644
--- a/libbb/libbb.h
+++ b/libbb/libbb.h
@@ -212,7 +212,7 @@ char *xreadlink(const char *path);
 char *concat_path_file(const char *path, const char *filename);
 char *last_char_is(const char *s, int c);
 
-extern long arith (const char *startbuf);
+extern long arith (const char *startbuf, int *errcode);
 
 typedef struct file_headers_s {
         char *name;
@@ -261,6 +261,8 @@ char *dirname (const char *path);
 
 int make_directory (char *path, mode_t mode, int flags);
 
+const char *u_signal_names(const char *str_sig, int *signo, int startnum);
+
 #define CT_AUTO 0
 #define CT_UNIX2DOS     1
 #define CT_DOS2UNIX     2