Read complex numbers where both parts are inexact decimals

Thanks to Bill Schottstaedt for reporting this problem!

* libguile/numbers.c (mem2ureal): Don't be misled by *p_exactness
  being INEXACT on entry (as is possible when reading a complex
  number): use local exactness variable x which starts as EXACT.
  Call mem2decimal_from_point () with &x instead of p_exactness.

* test-suite/tests/numbers.test ("string->number"): Add complex number
  tests suggested by Bill.

3 files changed, 22 insertions, 7 deletions

diff --git a/NEWS b/NEWS
index 235dcd5cc..0c21225f9 100644
--- a/NEWS
+++ b/NEWS
@@ -18,6 +18,7 @@ Changes in 1.8.7 (since 1.8.6)
 ** With GCC, always compile with `-mieee' on `alpha*' and `sh*'
 ** Better diagnose broken `(strftime "%z" ...)' in `time.test' (bug #24130)
 ** Fix parsing of SRFI-88/postfix keywords longer than 128 characters
+** Fix reading of complex numbers where both parts are inexact decimals
 
 ** Allow @ macro to work with (ice-9 syncase)
 
diff --git a/libguile/numbers.c b/libguile/numbers.c
index 25b0c1a62..2e1635faf 100644
--- a/libguile/numbers.c
+++ b/libguile/numbers.c
@@ -2739,6 +2739,10 @@ mem2ureal (const char* mem, size_t len, unsigned int *p_idx,
   unsigned int idx = *p_idx;
   SCM result;
 
+  /* Start off believing that the number will be exact.  This changes
+     to INEXACT if we see a decimal point or a hash. */
+  enum t_exactness x = EXACT;
+
   if (idx == len)
     return SCM_BOOL_F;
 
@@ -2750,8 +2754,6 @@ mem2ureal (const char* mem, size_t len, unsigned int *p_idx,
 
   if (idx+4 < len && !strncmp (mem+idx, "nan.", 4))
     {
-      enum t_exactness x = EXACT;
-
       /* Cobble up the fractional part.  We might want to set the
 	 NaN's mantissa from it. */
       idx += 4;
@@ -2770,11 +2772,10 @@ mem2ureal (const char* mem, size_t len, unsigned int *p_idx,
 	return SCM_BOOL_F;
       else
 	result = mem2decimal_from_point (SCM_I_MAKINUM (0), mem, len,
-					 p_idx, p_exactness);
+					 p_idx, &x);
     }
   else
     {
-      enum t_exactness x = EXACT;
       SCM uinteger;
 
       uinteger = mem2uinteger (mem, len, &idx, radix, &x);
@@ -2806,10 +2807,16 @@ mem2ureal (const char* mem, size_t len, unsigned int *p_idx,
 	result = uinteger;
 
       *p_idx = idx;
-      if (x == INEXACT)
-	*p_exactness = x;
     }
 
+  /* Update *p_exactness if the number just read was inexact.  This is
+     important for complex numbers, so that a complex number is
+     treated as inexact overall if either its real or imaginary part
+     is inexact.
+  */
+  if (x == INEXACT)
+    *p_exactness = x;
+
   /* When returning an inexact zero, make sure it is represented as a
      floating point value so that we can change its sign. 
   */
diff --git a/test-suite/tests/numbers.test b/test-suite/tests/numbers.test
index 2dbc917df..bafd9cd2c 100644
--- a/test-suite/tests/numbers.test
+++ b/test-suite/tests/numbers.test
@@ -1365,7 +1365,14 @@
                 ("1@0" 1.0) ("1@+0" 1.0) ("1@-0" 1.0)
                 ("2+3i" ,(+ 2 (* 3 +i))) ("4-5i" ,(- 4 (* 5 +i)))
                 ("1+i" 1+1i) ("1-i" 1-1i) ("+1i" 0+1i) ("-1i" 0-1i)
-                ("+i" +1i) ("-i" -1i)))
+                ("+i" +1i) ("-i" -1i)
+		("1.0+.1i" 1.0+0.1i)
+		("1.0-.1i" 1.0-0.1i)
+		(".1+.0i" 0.1)
+		("1.+.0i" 1.0)
+		(".1+.1i" 0.1+0.1i)
+		("1e1+.1i" 10+0.1i)
+		))
     #t)
 
   (pass-if-exception "exponent too big"