ash: fix $IFS handling in read. closes bug 235

diff --git a/shell/ash.c b/shell/ash.c
index 13b4329b55f25fc433d6473754f21e65f236370f..1de989ef31988671419071db93c6a45cd1fb7523 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -12574,7 +12574,7 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 #endif
 
        status = 0;
-       startword = 1;
+       startword = 2;
        backslash = 0;
 #if ENABLE_ASH_READ_TIMEOUT
        if (timeout) /* NB: ensuring end_ms is nonzero */
@@ -12582,6 +12582,8 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 #endif
        STARTSTACKSTR(p);
        do {
+               const char *is_ifs;
+
 #if ENABLE_ASH_READ_TIMEOUT
                if (end_ms) {
                        struct pollfd pfd[1];
@@ -12611,25 +12613,34 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
                        continue;
                }
                if (!rflag && c == '\\') {
-                       backslash++;
+                       backslash = 1;
                        continue;
                }
                if (c == '\n')
                        break;
-               if (startword && *ifs == ' ' && strchr(ifs, c)) {
-                       continue;
+               is_ifs = strchr(ifs, c);
+               if (startword && is_ifs) {
+                       if (isspace(c))
+                               continue;
+                       /* non-space ifs char */
+                       startword--;
+                       if (startword == 1) /* first one? */
+                               continue;
                }
                startword = 0;
-               if (ap[1] != NULL && strchr(ifs, c) != NULL) {
+               if (ap[1] != NULL && is_ifs) {
+                       const char *beg;
                        STACKSTRNUL(p);
-                       setvar(*ap, stackblock(), 0);
+                       beg = stackblock();
+                       setvar(*ap, beg, 0);
                        ap++;
-                       startword = 1;
+                       /* can we skip one non-space ifs? (2: yes) */
+                       startword = isspace(c) ? 2 : 1;
                        STARTSTACKSTR(p);
-               } else {
- put:
-                       STPUTC(c, p);
+                       continue;
                }
+ put:
+               STPUTC(c, p);
        }
 /* end of do {} while: */
 #if ENABLE_ASH_READ_NCHARS
@@ -12643,8 +12654,8 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 #endif
 
        STACKSTRNUL(p);
-       /* Remove trailing blanks */
-       while ((char *)stackblock() <= --p && strchr(ifs, *p) != NULL)
+       /* Remove trailing space ifs chars */
+       while ((char *)stackblock() <= --p && isspace(*p) && strchr(ifs, *p) != NULL)
                *p = '\0';
        setvar(*ap, stackblock(), 0);
        while (*++ap != NULL)

diff --git a/shell/ash_test/ash-read/read_ifs.right b/shell/ash_test/ash-read/read_ifs.right
new file mode 100644 (file)
index 0000000..027ecd1
--- /dev/null
+++ b/shell/ash_test/ash-read/read_ifs.right
@@ -0,0 +1,7 @@
+.a. .b. .c.
+.a. .b. .c.
+.a. .. .b,c.
+.a. .. .b,c.
+.a. .. .c.
+.a. .. .c. .d.
+.a. .. .b,c,d  ,  ,.

diff --git a/shell/ash_test/ash-read/read_ifs.tests b/shell/ash_test/ash-read/read_ifs.tests
new file mode 100755 (executable)
index 0000000..cf7cd93
--- /dev/null
+++ b/shell/ash_test/ash-read/read_ifs.tests
@@ -0,0 +1,7 @@
+printf 'a\t\tb\tc\n' | ( IFS=$(printf "\t") read a b c; echo ".$a. .$b. .$c." )
+printf 'a\t\tb\tc\n' | ( IFS=$(printf " \t") read a b c; echo ".$a. .$b. .$c." )
+printf 'a,,b,c\n'    | ( IFS="," read a b c; echo ".$a. .$b. .$c." )
+printf 'a,,b,c\n'    | ( IFS=" ," read a b c; echo ".$a. .$b. .$c." )
+printf 'a ,, c\n'    | ( IFS=" ," read a b c; echo ".$a. .$b. .$c." )
+printf 'a ,, c d\n'  | ( IFS=" ," read a b c d; echo ".$a. .$b. .$c. .$d." )
+printf ' a,,b,c,d  ,  ,\n' | ( IFS=" ," read a b c; echo ".$a. .$b. .$c." )