From 32c97093db85c827ccbbf4cd4255190718863232 Mon Sep 17 00:00:00 2001
From: =?utf8?q?P=C3=A1draig=20Brady?= <P@draigBrady.com>
Date: Tue, 23 Jun 2015 22:51:24 +0100
Subject: [PATCH] seq: handle exponents more consistently

src/seq.c (scan_arg): Set precision and width _after_ exponentiation.
For example, this will make '1.1e1 12' and '11 1.2e1' equivalent.
One can still set the precision by specifying extra precision on
the start value, or more naturally with a precision on a step value.
* tests/misc/seq-precision.sh: Add new cases.
---
 src/seq.c                   | 15 +++++++++++++--
 tests/misc/seq-precision.sh | 18 ++++++++++++++++++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/seq.c b/src/seq.c
index 95e6cd639c..2426c4de38 100644
--- a/src/seq.c
+++ b/src/seq.c
@@ -147,20 +147,24 @@ scan_arg (const char *arg)
   while (isspace (to_uchar (*arg)) || *arg == '+')
     arg++;
 
+  /* Default to auto width and precision.  */
   ret.width = 0;
   ret.precision = INT_MAX;
 
+  /* Use no precision (and possibly fast generation) for integers.  */
   char const *decimal_point = strchr (arg, '.');
   if (! decimal_point && ! strchr (arg, 'p') /* not a hex float */)
     ret.precision = 0;
 
+  /* auto set width and precision for decimal inputs.  */
   if (! arg[strcspn (arg, "xX")] && isfinite (ret.value))
     {
+      size_t fraction_len = 0;
       ret.width = strlen (arg);
 
       if (decimal_point)
         {
-          size_t fraction_len = strcspn (decimal_point + 1, "eE");
+          fraction_len = strcspn (decimal_point + 1, "eE");
           if (fraction_len <= INT_MAX)
             ret.precision = fraction_len;
           ret.width += (fraction_len == 0                      /* #.  -> #   */
@@ -174,7 +178,8 @@ scan_arg (const char *arg)
       if (e)
         {
           long exponent = strtol (e + 1, NULL, 10);
-          ret.precision += exponent < 0 ? -exponent : 0;
+          ret.precision += exponent < 0 ? -exponent
+                                        : - MIN (ret.precision, exponent);
           /* Don't account for e.... in the width since this is not output.  */
           ret.width -= strlen (arg) - (e - arg);
           /* Adjust the width as per the exponent.  */
@@ -189,6 +194,12 @@ scan_arg (const char *arg)
                 ret.width++;
               exponent = -exponent;
             }
+          else
+            {
+              if (decimal_point && ret.precision == 0 && fraction_len)
+                ret.width--; /* discount space for '.'  */
+              exponent -= MIN (fraction_len, exponent);
+            }
           ret.width += exponent;
         }
     }
diff --git a/tests/misc/seq-precision.sh b/tests/misc/seq-precision.sh
index e6a2bd7b81..b8382ca19c 100755
--- a/tests/misc/seq-precision.sh
+++ b/tests/misc/seq-precision.sh
@@ -58,4 +58,22 @@ seq 1 .1 0x2 | head -n2 > out || fail=1
 printf "%s\n" 1.0 1.1 > exp || framework_failure_
 compare exp out || fail=1
 
+# Ensure consistent handling of precision/width for exponents
+
+seq 1.1e1 12 > out || fail=1
+printf "%s\n" 11 12 > exp || framework_failure_
+compare exp out || fail=1
+
+seq 11 1.2e1 > out || fail=1
+printf "%s\n" 11 12 > exp || framework_failure_
+compare exp out || fail=1
+
+seq -w 1.1e4 | head -n1 > out || fail=1
+printf "%s\n" 00001 > exp || framework_failure_
+compare exp out || fail=1
+
+seq -w 1.10000e5 1.10000e5 > out || fail=1
+printf "%s\n" 110000 > exp || framework_failure_
+compare exp out || fail=1
+
 Exit $fail
-- 
2.47.2