Fix long lines in lib_calc.c

Fixed a segfault when getpwuid() returned NULL during initialization.
Thanks goes to baratharon GitHub user for reporting this issue.

CHANGES

@@ -1,4 +1,25 @@
-The following are the changes from calc version 2.12.7.0 to date:
+The following are the changes from calc version 2.12.7.1 to date:
+
+    Corrected CHANGES notes that were mixed up for TAB, VT, CR &
+    NL.  The code in 2.12.7.0 is correct.  The CHANGE notes should
+    have read:
+
+	The following is a partial list of escape sequences recognized
+	in strings and in printf formats:
+
+	    \a	audible bell	byte 0x07 in ASCII encoding
+	    \b	backspace	byte 0x08 in ASCII encoding
+	    \f	form feed	byte 0x0c in ASCII encoding
+	    \n	newline		byte 0x0a in ASCII encoding
+	    \r	return		byte 0x0d in ASCII encoding
+	    \t	tab		byte 0x09 in ASCII encoding
+	    \v	vertical tab	byte 0x0b in ASCII encoding
+
+     Fixed a segfault when getpwuid() returned NULL during initialization.
+     Thanks goes to baratharon GitHub user for reporting this issue.
+
+
+The following are the changes from calc version 2.12.6.10: to 2.12.7.0:
 
     Added a patch to replaces the manual search for include files
     in $(INCDIR) in the have_*.h targets with compiler invocations.
@@ -32,10 +53,10 @@ The following are the changes from calc version 2.12.7.0 to date:
 	\a	audible bell	byte 0x07 in ASCII encoding
 	\b	backspace	byte 0x08 in ASCII encoding
 	\f	form feed	byte 0x0c in ASCII encoding
-	\n	newline		byte 0x0b in ASCII encoding
-	\r	return		byte 0x0a in ASCII encoding
-	\t	tab		byte 0x0d in ASCII encoding
-	\v	vertical tab	byte 0x09 in ASCII encoding
+	\n	newline		byte 0x0a in ASCII encoding
+	\r	return		byte 0x0d in ASCII encoding
+	\t	tab		byte 0x09 in ASCII encoding
+	\v	vertical tab	byte 0x0b in ASCII encoding
 
 
 The following are the changes from calc version 2.12.6.9 to 2.12.6.9:

Makefile.ship

@@ -1054,7 +1054,7 @@ EXT=
 
 # The default calc versions
 #
-VERSION= 2.12.7.0
+VERSION= 2.12.7.2
 
 # Names of shared libraries with versions
 #

custom/Makefile

@@ -348,7 +348,7 @@ EXT=
 
 # The default calc versions
 #
-VERSION= 2.12.7.0
+VERSION= 2.12.7.2
 
 # Names of shared libraries with versions
 #

custom/Makefile.head

@@ -348,7 +348,7 @@ EXT=
 
 # The default calc versions
 #
-VERSION= 2.12.7.0
+VERSION= 2.12.7.2
 
 # Names of shared libraries with versions
 #

lib_calc.c

@@ -1,7 +1,7 @@
 /*
  * lib_calc - calc link library initialization and shutdown routines
  *
- * Copyright (C) 1999-2007  Landon Curt Noll
+ * Copyright (C) 1999-2007,2018  Landon Curt Noll
  *
  * Calc is open software; you can redistribute it and/or modify it under
  * the terms of the version 2.1 of the GNU Lesser General Public License
@@ -504,22 +504,36 @@ initenv(void)
 	home = (c ? strdup(c) : NULL);
 #if defined(_WIN32)
 	if (home == NULL || home[0] == '\0') {
+		/* free home if it was previously allocated, but empty */
+		if (home != NULL) {
+			free(home);
+		}
 		/* just assume . is home if all else fails */
-		home = ".";
+		home = strdup(".");
 	}
 #else /* Windoz free systems */
 	if (home == NULL || home[0] == '\0') {
-		size_t pw_dir_len;
-		ent = (struct passwd *)getpwuid(geteuid());
-		if (ent == NULL) {
-			/* just assume . is home if all else fails */
-			home = ".";
+		/* free home if it was previously allocated, but empty */
+		if (home != NULL) {
+			free(home);
+		}
+		/* try using the home directory of current effective UID */
+		ent = (struct passwd *)getpwuid(geteuid());
+		if (ent == NULL || ent->pw_dir == NULL ||
+		    ent->pw_dir[0] == '\0') {
+			/* just assume . is home if all else fails */
+			home = strdup(".");
+		} else {
+			/* use home directory of current effective UID */
+			home = strdup(ent->pw_dir);
 		}
-		pw_dir_len = strlen(ent->pw_dir);
-		home = (char *)malloc(pw_dir_len+1);
-		strncpy(home, ent->pw_dir, pw_dir_len+1);
 	}
 #endif /* Windoz free systems */
+	/* paranoia */
+	if (home == NULL) {
+		math_error("Unable to allocate string for $HOME");
+		/*NOTREACHED*/
+	}
 
 	/* determine the $PAGER value */
 	c = (no_env ? NULL : getenv(PAGER));

version.c

@@ -45,7 +45,7 @@ static char *program;
 #define MAJOR_VER	2	/* major library version */
 #define MINOR_VER	12	/* minor library version */
 #define MAJOR_PATCH	7	/* major software level under library version */
-#define MINOR_PATCH	0	/* minor software level or 0 if not patched */
+#define MINOR_PATCH	2	/* minor software level or 0 if not patched */
 
 
 /*