- avoid division-by-zero crash in tabwriter

- correct tabwidth argument for some tabwriter test cases
- catch negative tabwidth flag in gofmt w/o crashing

R=rsc
http://go/go-review/1026022

diff --git a/src/cmd/gofmt/gofmt.go b/src/cmd/gofmt/gofmt.go
index 4fab0aec4f961b2fb9e37da4b37c25eac0af62e6..b554c4f1514681ebec69ed91df80c2ccec626fd1 100644 (file)
--- a/src/cmd/gofmt/gofmt.go
+++ b/src/cmd/gofmt/gofmt.go
@@ -153,6 +153,10 @@ func walkDir(path string) {
 func main() {
        flag.Usage = usage;
        flag.Parse();
+       if *tabwidth < 0 {
+               fmt.Fprintf(os.Stderr, "negative tabwidth %d\n", *tabwidth);
+               os.Exit(2);
+       }
 
        if flag.NArg() == 0 {
                if err := processFile("/dev/stdin"); err != nil {

diff --git a/src/pkg/tabwriter/tabwriter.go b/src/pkg/tabwriter/tabwriter.go
index 9370bb4a0b2ebbca5f1daacb2d4e6faebbe6d881..0946f2edd5319d34b9158b72ce4646a56e828e42 100644 (file)
--- a/src/pkg/tabwriter/tabwriter.go
+++ b/src/pkg/tabwriter/tabwriter.go
@@ -229,6 +229,10 @@ func (b *Writer) write0(buf []byte) os.Error {
 var newline = []byte{'\n'}
 
 func (b *Writer) writePadding(textw, cellw int) os.Error {
+       if b.cellwidth == 0 {
+               return nil;
+       }
+
        if b.padbytes[0] == '\t' {
                // make cell width a multiple of cellwidth
                cellw = ((cellw + b.cellwidth - 1) / b.cellwidth) * b.cellwidth;

diff --git a/src/pkg/tabwriter/tabwriter_test.go b/src/pkg/tabwriter/tabwriter_test.go
index 6016e36cfefdbed0a1a095a00395b339b00a566d..1f52eef8273f0bd6caf137cefabbedb4c92e6f6d 100644 (file)
--- a/src/pkg/tabwriter/tabwriter_test.go
+++ b/src/pkg/tabwriter/tabwriter_test.go
@@ -283,7 +283,7 @@ var tests = []entry{
 
        entry{
                "9a",
-               0, 0, '.', 0,
+               1, 0, '.', 0,
                "1\t2\t3\t4\n"
                        "11\t222\t3333\t44444\n",
 
@@ -293,7 +293,7 @@ var tests = []entry{
 
        entry{
                "9b",
-               0, 0, '.', FilterHTML,
+               1, 0, '.', FilterHTML,
                "1\t2<!---\f--->\t3\t4\n"       // \f inside HTML is ignored
                        "11\t222\t3333\t44444\n",
 
@@ -303,7 +303,7 @@ var tests = []entry{
 
        entry{
                "9c",
-               0, 0, '.', 0,
+               1, 0, '.', 0,
                "1\t2\t3\t4\f"  // \f causes a newline and flush
                        "11\t222\t3333\t44444\n",
 
@@ -313,7 +313,7 @@ var tests = []entry{
 
        entry{
                "9c debug",
-               0, 0, '.', Debug,
+               1, 0, '.', Debug,
                "1\t2\t3\t4\f"  // \f causes a newline and flush
                        "11\t222\t3333\t44444\n",
 
@@ -445,7 +445,7 @@ var tests = []entry{
 
        entry{
                "14",
-               0, 2, ' ', AlignRight,
+               1, 2, ' ', AlignRight,
                ".0\t.3\t2.4\t-5.1\t\n"
                        "23.0\t12345678.9\t2.4\t-989.4\t\n"
                        "5.1\t12.0\t2.4\t-7.0\t\n"
@@ -463,7 +463,7 @@ var tests = []entry{
 
        entry{
                "14 debug",
-               0, 2, ' ', AlignRight | Debug,
+               1, 2, ' ', AlignRight | Debug,
                ".0\t.3\t2.4\t-5.1\t\n"
                        "23.0\t12345678.9\t2.4\t-989.4\t\n"
                        "5.1\t12.0\t2.4\t-7.0\t\n"